Bump org.jetbrains.kotlin.jvm from 2.0.20 to 2.0.21

Bumps [org.jetbrains.kotlin.jvm](https://github.com/JetBrains/kotlin) from 2.0.20 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@v2.0.20...v2.0.21)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin.jvm
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

gradle/libs.versions.toml

@@ -8,7 +8,7 @@ junit = "4.13.2"
 websocket = "1.5.7"
 
 # plugins
-kotlin = "2.0.20"
+kotlin = "2.0.21"
 kover = "0.8.3"
 changelog = "2.2.1"
 gradleIntelliJPlugin = "1.17.4"