Bump org.jetbrains.kotlin:kotlin-stdlib-jdk8 from 1.8.20 to 1.8.21

Bumps [org.jetbrains.kotlin:kotlin-stdlib-jdk8](https://github.com/JetBrains/kotlin) from 1.8.20 to 1.8.21.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.8.20...v1.8.21)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin:kotlin-stdlib-jdk8
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

gradle-versions-plugin/build.gradle

@@ -29,7 +29,7 @@ dependencies {
   compileOnly gradleApi()
 
   implementation localGroovy()
-  implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.8.20'
+  implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.8.21'
   implementation 'org.jetbrains.kotlin:kotlin-reflect:1.8.20'
   implementation 'com.squareup.okhttp3:okhttp:4.10.0'
   implementation 'com.squareup.moshi:moshi-kotlin:1.12.0'