Bump checker from 4.1.0 to 4.2.0

Bumps `checker` from 4.1.0 to 4.2.0.

Updates `org.checkerframework:checker` from 4.1.0 to 4.2.0
- [Release notes](https://github.com/typetools/checker-framework/releases)
- [Changelog](https://github.com/typetools/checker-framework/blob/master/docs/CHANGELOG.md)
- [Commits](typetools/checker-framework@checker-framework-4.1.0...checker-framework-4.2.0)

Updates `org.checkerframework:checker-qual` from 4.1.0 to 4.2.0
- [Release notes](https://github.com/typetools/checker-framework/releases)
- [Changelog](https://github.com/typetools/checker-framework/blob/master/docs/CHANGELOG.md)
- [Commits](typetools/checker-framework@checker-framework-4.1.0...checker-framework-4.2.0)

---
updated-dependencies:
- dependency-name: org.checkerframework:checker
  dependency-version: 4.2.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.checkerframework:checker-qual
  dependency-version: 4.2.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -7,7 +7,7 @@ build-plugins = "2026.3"
 
 # using the embedded kotlin version of Gradle to avoid mixed versions
 kotlin = "2.3.0"
-checker = "4.1.0"
+checker = "4.2.0"
 checkerp = "0.6.61"
 jacoco = "0.8.11"
 jacocolog = "4.0.1"