Bump kotlin.version from 1.7.20 to 1.7.21

Bumps `kotlin.version` from 1.7.20 to 1.7.21.

Updates `kotlin-maven-plugin` from 1.7.20 to 1.7.21

Updates `kotlin-stdlib-jdk8` from 1.7.20 to 1.7.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/commits)

Updates `kotlin-maven-serialization` from 1.7.20 to 1.7.21

Updates `kotlin-reflect` from 1.7.20 to 1.7.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/commits)

Updates `kotlin-gradle-plugin` from 1.7.20 to 1.7.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/commits)

Updates `kotlin-test` from 1.7.20 to 1.7.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/commits)

Updates `kotlin-maven-allopen` from 1.7.20 to 1.7.21

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin:kotlin-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin:kotlin-stdlib-jdk8
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin:kotlin-maven-serialization
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin:kotlin-reflect
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin:kotlin-gradle-plugin
  dependency-type: direct:development
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin:kotlin-test
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin:kotlin-maven-allopen
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

build-parent/pom.xml

@@ -20,7 +20,7 @@
         <!-- These properties are needed in order for them to be resolvable by the generated projects -->
         <!-- Quarkus uses jboss-parent and it comes with 3.8.1-jboss-1, we don't want that in the templates -->
         <compiler-plugin.version>3.8.1</compiler-plugin.version>
-        <kotlin.version>1.7.20</kotlin.version>
+        <kotlin.version>1.7.21</kotlin.version>
         <dokka.version>1.7.20</dokka.version>
         <scala.version>2.13.8</scala.version>
         <scala-maven-plugin.version>4.7.2</scala-maven-plugin.version>