Kotlin api and language version 2.0

[jangalinski]

Scenario

Because there where problems in the past, we reduced the versions to 1.9. We should check if this is required anymore ... expectation: not needed, go for 2.0

  <properties>
    <!-- use 1.9 because experimental kotlin poet and serialization led to Fir-errors. -->
    <kotlin.compiler.apiVersion>1.9</kotlin.compiler.apiVersion>
    <kotlin.compiler.languageVersion>1.9</kotlin.compiler.languageVersion>
  </properties>

• Library version:
• Description of your use case: (detailed description or executable reproducer, e.g. GitHub repo)