Bump kotlin from 1.9.10 to 1.9.20 (#63)

Bumps `kotlin` from 1.9.10 to 1.9.20.

Updates `org.jetbrains.kotlin:kotlin-gradle-plugin` from 1.9.10 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)

Updates `org.jetbrains.kotlin:kotlin-reflect` from 1.9.10 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)

Updates `org.jetbrains.kotlin:kotlin-stdlib-jdk8` from 1.9.10 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-patch
- dependency-name: org.jetbrains.kotlin:kotlin-reflect
  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
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

gradle/libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 gson = "2.10.1"
-kotlin = "1.9.10"
+kotlin = "1.9.20"
 kotest = "5.7.2"
 dokka = "1.9.10"
 nexus-publish-gradle-plugin = "1.3.0"