MINOR: redundant scala-related code block is removed

[dejan2609]

💡 Rationale: Kafka is now using a single Scala version.

Notes:

1. I would even go further and remove references for baseScala given the fact that they now always resolve to versions.scala
2. Also: scalaVersion can be removed from gradle.properties, and hence just a single line would be sufficient:

dependencies.gradle
...
   versions += [
   ...
   scala: "2.13.17",
   ...
   ]

LMKWYT @chia7712

[dejan2609]

@omkreddy 🤝