chore: drop unused borrow_deref_ref allows

Seven `#[allow(clippy::borrow_deref_ref)]` attributes on module
declarations in `crates/core/src/lib.rs` had become stale — the only
remaining lint hit was a redundant `&*x.as_str()` pattern in
`parse_file_compression_type`. Rewriting that call to
`&x.unwrap_or_default()` lets every allow come off, removing noise that
new modules were copying without need.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: timsaucer

crates/core/src/context.rs

@@ -1576,10 +1576,9 @@ impl PySessionContext {
 pub fn parse_file_compression_type(
     file_compression_type: Option<String>,
 ) -> Result<FileCompressionType, PyErr> {
-    FileCompressionType::from_str(&*file_compression_type.unwrap_or("".to_string()).as_str())
-        .map_err(|_| {
-            PyValueError::new_err("file_compression_type must one of: gzip, bz2, xz, zstd")
-        })
+    FileCompressionType::from_str(&file_compression_type.unwrap_or_default()).map_err(|_| {
+        PyValueError::new_err("file_compression_type must one of: gzip, bz2, xz, zstd")
+    })
 }
 
 impl From<PySessionContext> for SessionContext {

crates/core/src/lib.rs

@@ -26,29 +26,23 @@ pub use datafusion_substrait;
 use mimalloc::MiMalloc;
 use pyo3::prelude::*;
 
-#[allow(clippy::borrow_deref_ref)]
 pub mod catalog;
 pub mod codec;
 pub mod common;
 
-#[allow(clippy::borrow_deref_ref)]
 pub mod context;
-#[allow(clippy::borrow_deref_ref)]
 pub mod dataframe;
 mod dataset;
 mod dataset_exec;
 pub mod errors;
-#[allow(clippy::borrow_deref_ref)]
 pub mod expr;
-#[allow(clippy::borrow_deref_ref)]
 mod functions;
 pub mod metrics;
 mod options;
 pub mod physical_plan;
 mod pyarrow_filter_expression;
 pub mod pyarrow_util;
 mod record_batch;
-#[allow(clippy::borrow_deref_ref)]
 mod spark_functions;
 pub mod sql;
 pub mod store;
@@ -58,9 +52,7 @@ pub mod unparser;
 mod array;
 #[cfg(feature = "substrait")]
 pub mod substrait;
-#[allow(clippy::borrow_deref_ref)]
 mod udaf;
-#[allow(clippy::borrow_deref_ref)]
 mod udf;
 pub mod udtf;
 mod udwf;