reproducible builds: cassandra-bundle.jar is not always rebuilt when needed

Checking the 1.1.0 release, I found the cassandra-bundle.jar was a version `1.1.0-M0+73-9c76067f+20240712-1357-SNAPSHOT` one, rather than a freshly-built one.

It seems `sbt +clean` does not remove `target/cassandra-bundle.jar`.

As a workaround perhaps we should manually clean out `cassandra-bundle/target` as part of the release process?

Start by reproducing the release behavior around sbt +clean and the target/cassandra-bundle.jar path, then inspect how the cassandra-bundle/target directory is handled during releases. Done means the release process reliably rebuilds cassandra-bundle.jar instead of packaging the older snapshot artifact.

Written by the indexing model from the issue text.