chore: prune stale NOTICE.txt entries, add mini-redis attribution

[andygrove]

Disclaimer: this PR was prepared by an LLM (Claude Code) at my request, against ad129930. The claim that each removed entry has no counterpart in the tree was checked by grepping the repo, and the mini-redis copyright line was fetched from upstream's LICENSE rather than recalled — but please treat the licensing judgement calls as suggestions and push back where they're wrong.

Which issue does this PR close?

N/A — housekeeping, no issue filed.

Rationale for this change

NOTICE.txt was inherited when Ballista was split out of the Arrow repo, and still lists bundled works that Ballista does not contain. Everything removed below is an Arrow C++ or build-system artifact with no counterpart in this pure-Rust repo:

Removed entry	Why it doesn't apply
LLVM	No C++; the only llvm match in the tree is a passing mention in a doc comment (ballista/core/src/kll.rs:337)
google-lint (cpplint)	No C++ to lint
CMake (two entries)	No CMake build
Jekyll	Docs are Sphinx; the only jekyll match is touch .nojekyll in .github/workflows/docs.yaml
Apache Kudu	No Kudu code
Apache ORC	No ORC code or ORC support

Carrying entries for software we don't ship makes the file misleading about what's actually bundled, which is the one thing NOTICE.txt exists to communicate.

What changes are included in this PR?

NOTICE.txt — reduced to the required ASF attribution, and the copyright end year refreshed to 2026:

Apache DataFusion Ballista
Copyright 2016-2026 The Apache Software Foundation

This product includes software developed at
The Apache Software Foundation (http://www.apache.org/).

LICENSE.txt — while auditing what is bundled, ballista/executor/src/shutdown.rs turned out to be based on Tokio's mini-redis example (MIT) and was not attributed anywhere. Added an entry after the existing Apache Aurora one, with the full MIT text inline, since MIT requires the notice and permission text travel with the code — a URL alone isn't sufficient the way it is for the Apache-2.0 Aurora entry.

The split follows ASF policy: NOTICE.txt carries only required ASF attribution, and third-party bundled works belong in LICENSE.txt. Two other copied-from sites were checked and need nothing — ballista-cli/src/tui/app.rs and .../aqe/execution_plan/dynamic_join.rs both copy from DataFusion, which is ASF Apache-2.0 with a plain NOTICE.

Are there any user-facing changes?

No code or API changes. The contents of NOTICE.txt and LICENSE.txt ship in release artifacts, so this is user-visible in that narrow sense.

[milenkovicm]

Thanks @andygrove