Automerge: [CI] Remove ccache from Linux CI Container

This patch removes ccache from the Linux CI container. It is no longer
needed after migrating the monolithic-linux.sh script. The other two
upstream users of this container, namely the post commit static analyzer
and the llvm tests workflow both already use sccache.

Reviewers: tstellar, gburgessiv, dschuff, Keenuts, lnihlen, cmtice

Reviewed By: dschuff, Keenuts, cmtice

Pull Request: llvm/llvm-project#149197

Author: boomanaiden154