chore(deps): bump org.jetbrains.kotlin:kotlin-gradle-plugin

Bumps [org.jetbrains.kotlin:kotlin-gradle-plugin](https://github.com/JetBrains/kotlin) from 1.5.21 to 1.9.20.
- [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)

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

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

build.gradle

@@ -15,7 +15,7 @@
  */
 buildscript {
     dependencies {
-        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.5.21'
+        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.9.20'
         classpath 'com.vanniktech:gradle-maven-publish-plugin:0.15.1'
     }