Kotlin: update to 2.3.20

[redsun82]

No description provided.

[Copilot]

Pull request overview

Updates the repository’s Kotlin toolchain support to Kotlin 2.3.20, aligning Bazel module deps, the Kotlin extractor’s supported-version list, dev tooling defaults, and accompanying tests/change notes.

Changes:

• Add Kotlin 2.3.20 compiler / embeddable compiler / stdlib artifacts to Bazel module repos and checked-in extractor deps.
• Extend the Kotlin extractor’s supported versions to include 2.3.20 and suppress newly introduced Kotlin 2.3.20 deprecations in a helper file.
• Update integration test expectations and add a Java QL change note for the new supported Kotlin version.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
MODULE.bazel	Adds kotlin-*-2.3.20 repositories to the kotlin_extractor_depsuse_repo list.
java/ql/lib/change-notes/2026-03-26-kotlin-2.3.20.md	Adds an unreleased change note announcing Kotlin support through 2.3.20.
java/ql/integration-tests/kotlin/all-platforms/diagnostics/kotlin-version-too-new/diagnostics.expected	Updates expected diagnostic message threshold for “version too new”.
java/ql/integration-tests/kotlin/all-platforms/annotation-id-consistency/PrintAst.expected	Updates expected AST output for Kotlin 2.3.20-related annotation structure changes.
java/kotlin-extractor/versions.bzl	Adds 2.3.20 to the supported Kotlin versions list used by Bazel deps.
java/kotlin-extractor/src/main/kotlin/utils/GetByFqName.kt	Suppresses deprecation warnings introduced in Kotlin 2.3.20 for referenced APIs.
java/kotlin-extractor/dev/wrapper.py	Bumps the dev wrapper’s default Kotlin version to 2.3.20.
java/kotlin-extractor/deps/kotlin-stdlib-2.3.20.jar	Adds LFS-tracked stdlib jar for 2.3.20.
java/kotlin-extractor/deps/kotlin-compiler-embeddable-2.3.20.jar	Adds LFS-tracked embeddable compiler jar for 2.3.20.
java/kotlin-extractor/deps/kotlin-compiler-2.3.20.jar	Adds LFS-tracked compiler jar for 2.3.20.
.pre-commit-config.yaml	Broadens the test-path exclusion pattern for whitespace/EOF hooks to cover test* directories.

[jketema]

Based on my current understanding of the update process, this LGTM.

Do we still want to run some DCA on this to see nothing has regressed?