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: https://github.com/llvm/llvm-project/pull/149197
0f3c94a3d8