Bump org.jetbrains.kotlin:kotlin-gradle-plugin from 1.9.24 to 2.0.21

Bumps [org.jetbrains.kotlin:kotlin-gradle-plugin](https://github.com/JetBrains/kotlin) from 1.9.24 to 2.0.21.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/v2.0.21/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.9.24...v2.0.21)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin:kotlin-gradle-plugin
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

gradle/libs.versions.toml

@@ -1,7 +1,7 @@
 [versions]
 # build tools
 java = "21"
-kotlin = "1.9.24"
+kotlin = "2.0.21"
 ktlint = "1.2.0"
 jacoco = "0.8.11"
 # dependencies