Revert "ci: Enable GALLIUM_DUMP_CPU=true only in the clang job"

Rob worded it well in 9e8450b6.

"We don't want util_cpu to vomit cpu caps all over the test output."

This reverts commit c6979d97.

Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Part-of: <mesa/mesa!27564>
(cherry picked from commit 62fa5c8d)