Remove cass-config-builder support

[burmanm]

What is missing?

The k8ssandra-client builds the necessary configs already, using a correct base configuration. cass-config-builder does not do this, but instead relies on some older base versions that are then appended with problematic ones.

At the moment, we do 4.1.x and up with k8ssandra-client and older ones with the cass-config-builder. That means extra maintenance burden.

Why is this needed?

Extra maintenance, extra problems.

┆Issue is synchronized with this Jira Story by Unito
┆Issue Number: CASS-9