Bump kotlin.version from 1.4.21 to 1.4.21-2

Bumps `kotlin.version` from 1.4.21 to 1.4.21-2.

Updates `kotlin-maven-plugin` from 1.4.21 to 1.4.21-2

Updates `kotlin-stdlib` from 1.4.21 to 1.4.21-2
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.4.21...v1.4.21-2)

Updates `kotlin-stdlib-common` from 1.4.21 to 1.4.21-2
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.4.21...v1.4.21-2)

Updates `kotlin-test-junit` from 1.4.21 to 1.4.21-2
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.4.21...v1.4.21-2)

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

pom.xml

@@ -94,7 +94,7 @@
         <maven.compiler.target>1.8</maven.compiler.target>
 
         <!-- Configuration of mutiny-kotlin module -->
-        <kotlin.version>1.4.21</kotlin.version>
+        <kotlin.version>1.4.21-2</kotlin.version>
         <kotlin.compiler.apiVersion>1.3</kotlin.compiler.apiVersion>
         <kotlin.compiler.languageVersion>1.3</kotlin.compiler.languageVersion>
         <coroutines.version>1.4.2</coroutines.version>