build(deps): bump kotlin.version from 2.2.20 to 2.2.21

Bumps `kotlin.version` from 2.2.20 to 2.2.21.

Updates `org.jetbrains.kotlin:kotlin-bom` from 2.2.20 to 2.2.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/v2.2.21/ChangeLog.md)
- [Commits](JetBrains/kotlin@v2.2.20...v2.2.21)

Updates `org.jetbrains.kotlin:kotlin-stdlib` from 2.2.20 to 2.2.21
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/v2.2.21/ChangeLog.md)
- [Commits](JetBrains/kotlin@v2.2.20...v2.2.21)

Updates `org.jetbrains.kotlin:kotlin-maven-allopen` from 2.2.20 to 2.2.21

Updates `org.jetbrains.kotlin:kotlin-maven-plugin` from 2.2.20 to 2.2.21

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin:kotlin-bom
  dependency-version: 2.2.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin:kotlin-stdlib
  dependency-version: 2.2.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin:kotlin-maven-allopen
  dependency-version: 2.2.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.jetbrains.kotlin:kotlin-maven-plugin
  dependency-version: 2.2.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

pom.xml

@@ -76,7 +76,7 @@
     <spring-boot.version>3.5.6</spring-boot.version>
     <ff4j.version>2.1</ff4j.version>
     <jackson-module-kotlin.version>2.20.0</jackson-module-kotlin.version>
-    <kotlin.version>2.2.20</kotlin.version>
+    <kotlin.version>2.2.21</kotlin.version>
     <cucumber.version>7.30.0</cucumber.version>
     <junit-jupiter.version>6.0.0</junit-jupiter.version>
     <springdoc-openapi-starter.version>2.8.13</springdoc-openapi-starter.version>