build(deps): Bump org.jetbrains.dokka from 1.7.0 to 1.9.20

Bumps [org.jetbrains.dokka](https://github.com/Kotlin/dokka) from 1.7.0 to 1.9.20.
- [Release notes](https://github.com/Kotlin/dokka/releases)
- [Commits](Kotlin/dokka@v1.7.0...v1.9.20)

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

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

gradle/libs.versions.toml

@@ -250,7 +250,7 @@ testing = [
 
 [plugins]
 resourceplaceholders = "de.timfreiheit.resourceplaceholders:0.2"
-dokka = "org.jetbrains.dokka:1.7.0"
+dokka = "org.jetbrains.dokka:1.9.20"
 sonarqube = "org.sonarqube:4.3.1.3277"
 detekt = "io.gitlab.arturbosch.detekt:1.23.1"
 versions = "com.github.ben-manes.versions:0.41.0"