Bump org.jetbrains.kotlin:kotlin-gradle-plugin from 1.6.10 to 1.6.21

Bumps [org.jetbrains.kotlin:kotlin-gradle-plugin](https://github.com/JetBrains/kotlin) from 1.6.10 to 1.6.21.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/v1.6.21/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.6.10...v1.6.21)

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

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

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -30,7 +30,7 @@ io-spring-nohttp-nohttp-checkstyle = { module = "io.spring.nohttp:nohttp-checkst
 io-spring-nohttp-nohttp-gradle = { module = "io.spring.nohttp:nohttp-gradle", version.ref = "io-spring-nohttp" }
 org-asciidoctor-asciidoctor-gradle-jvm-plugin = "org.asciidoctor:asciidoctor-gradle-jvm:3.3.2"
 org-asciidoctor-asciidoctor-gradle-jvm-pdf-plugin = "org.asciidoctor:asciidoctor-gradle-jvm-pdf:3.3.2"
-org-jetbrains-kotlin-kotlin-gradle-plugin = "org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.10"
+org-jetbrains-kotlin-kotlin-gradle-plugin = "org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.21"
 org-hidetake-gradle-ssh-plugin = "org.hidetake:gradle-ssh-plugin:2.10.1"
 org-jfrog-buildinfo-build-info-extractor-gradle = "org.jfrog.buildinfo:build-info-extractor-gradle:4.29.4"
 org-sonarsource-scanner-gradle-sonarqube-gradle-plugin = "org.sonarsource.scanner.gradle:sonarqube-gradle-plugin:2.7.1"