[CI] Disable werror for xpti on Mac (#22482)
We build on Mac in postcommit to verify we didn't break anything that
would be a problem for pulldown/upstreaming, but we don't run any tests.
A dependency to `xptifw`, `parallel-hashmap`, cause warnings during the
build on Mac, so just disable `werror` for XPTI/XPTIFW.
CI run:
https://github.com/intel/llvm/actions/runs/28386217398/job/84101462283
Signed-off-by: Nick Sarnie <nick.sarnie@intel.com>
