Fix and simplify constant_coalesce pass

[BramOtte]

Currently the constant coalesce pass is broken, it crashes the plot both on chungus2 and on mpu8.
This pull request fixes this issue and also simplifies the constant coalesce pass by only having 1 constant node instead of 1 for each signal strength

[BramOtte]

Stack trace
`ERROR mchprs_core::server: plot panicked at /home/bram/.cargo/registry/src/index.crates.io-6f17d22bba15001f/petgraph-0.7.1/src/graph_impl/stable_graph/mod.rs:402:17:
StableGraph::add_edge: node index 235438 is not a node in the graph
0: mchprs_core::server::MinecraftServer::run::{{closure}}
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/core/src/server.rs:142:29
1: <alloc::boxed::Box<F,A> as core::ops::function::Fn>::call
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/alloc/src/boxed.rs:1986:9
std::panicking::rust_panic_with_hook
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/std/src/panicking.rs:809:13
2: std::panicking::begin_panic_handler::{{closure}}
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/std/src/panicking.rs:674:13
3: std::sys::backtrace::__rust_end_short_backtrace
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/std/src/sys/backtrace.rs:170:18
4: rust_begin_unwind
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/std/src/panicking.rs:665:5
5: core::panicking::panic_fmt
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/core/src/panicking.rs:76:14
6: petgraph::graph_impl::stable_graph::StableGraph<N,E,Ty,Ix>::add_edge
at /home/bram/.cargo/registry/src/index.crates.io-6f17d22bba15001f/petgraph-0.7.1/src/graph_impl/stable_graph/mod.rs:402:17
7: <mchprs_redpiler::passes::constant_coalesce::ConstantCoalesce as mchprs_redpiler::passes::Pass>::run_pass
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/redpiler/src/passes/constant_coalesce.rs:56:17
8: mchprs_redpiler::passes::PassManager::run_passes
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/redpiler/src/passes/mod.rs:73:13
9: mchprs_redpiler::Compiler::compile
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/redpiler/src/lib.rs:135:21
10: mchprs_core::plot::Plot::start_redpiler::{{closure}}::{{closure}}
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/core/src/plot/mod.rs:697:17
std::sys::backtrace::rust_begin_short_backtrace
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/sys/backtrace.rs:154:18
11: std::thread::Builder::spawn_unchecked::{{closure}}::{{closure}}
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/thread/mod.rs:561:17
<core::panic::unwind_safe::AssertUnwindSafe as core::ops::function::FnOnce<()>>::call_once
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:272:9
std::panicking::try::do_call
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:557:40
std::panicking::try
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:520:19
std::panic::catch_unwind
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panic.rs:358:14
std::thread::Builder::spawn_unchecked::{{closure}}
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/thread/mod.rs:559:30
core::ops::function::FnOnce::call_once{{vtable.shim}}
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5
12: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce>::call_once
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/alloc/src/boxed.rs:1972:9
<alloc::boxed::Box<F,A> as core::ops::function::FnOnce>::call_once
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/alloc/src/boxed.rs:1972:9
std::sys::pal::unix::thread::Thread::new::thread_start
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/std/src/sys/pal/unix/thread.rs:105:17
13: start_thread
at ./nptl/pthread_create.c:442:8
14: __GI___clone3
at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81:0

2025-02-05T18:53:55.869953Z ERROR mchprs_core::server: plot panicked at crates/core/src/plot/mod.rs:695:9:
a scoped thread panicked
0: mchprs_core::server::MinecraftServer::run::{{closure}}
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/core/src/server.rs:142:29
1: <alloc::boxed::Box<F,A> as core::ops::function::Fn>::call
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/alloc/src/boxed.rs:1986:9
std::panicking::rust_panic_with_hook
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/std/src/panicking.rs:809:13
2: std::panicking::begin_panic_handler::{{closure}}
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/std/src/panicking.rs:667:13
3: std::sys::backtrace::__rust_end_short_backtrace
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/std/src/sys/backtrace.rs:170:18
4: rust_begin_unwind
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/std/src/panicking.rs:665:5
5: core::panicking::panic_fmt
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/core/src/panicking.rs:76:14
6: std::thread::scoped::scope
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/thread/scoped.rs:162:13
7: mchprs_core::plot::Plot::start_redpiler
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/core/src/plot/mod.rs:695:9
8: mchprs_core::plot::commands::::handle_redpiler_command
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/core/src/plot/commands.rs:189:17
mchprs_core::plot::commands::::handle_command
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/core/src/plot/commands.rs:403:17
mchprs_core::plot::Plot::handle_commands
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/core/src/plot/mod.rs:843:20
9: mchprs_core::plot::Plot::update
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/core/src/plot/mod.rs:1066:9
10: mchprs_core::plot::Plot::run
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/core/src/plot/mod.rs:1213:17
11: mchprs_core::plot::Plot::load_and_run::{{closure}}
at /home/bram/SynologyDrive/sync/coding/mchprs/MCHPRS/crates/core/src/plot/mod.rs:1259:37
std::sys::backtrace::rust_begin_short_backtrace
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/sys/backtrace.rs:154:18
12: std::thread::Builder::spawn_unchecked::{{closure}}::{{closure}}
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/thread/mod.rs:561:17
<core::panic::unwind_safe::AssertUnwindSafe as core::ops::function::FnOnce<()>>::call_once
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:272:9
std::panicking::try::do_call
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:557:40
std::panicking::try
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:520:19
std::panic::catch_unwind
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panic.rs:358:14
std::thread::Builder::spawn_unchecked::{{closure}}
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/thread/mod.rs:559:30
core::ops::function::FnOnce::call_once{{vtable.shim}}
at /home/bram/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5
13: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce>::call_once
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/alloc/src/boxed.rs:1972:9
<alloc::boxed::Box<F,A> as core::ops::function::FnOnce>::call_once
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/alloc/src/boxed.rs:1972:9
std::sys::pal::unix::thread::Thread::new::thread_start
at /rustc/e71f9a9a98b0faf423844bf0ba7438f29dc27d58/library/std/src/sys/pal/unix/thread.rs:105:17
14: start_thread
at ./nptl/pthread_create.c:442:8
15: __GI___clone3
at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81:0`

[BramOtte]

The crash this PR fixes is already resolved in another PR and the simplification is also already present in #222
Since there is no urgency for this fix the simplification can simply come with PR 222 thus I am closing this PR.