Revert "[OpenMP] Disable flaky barrier fence test (#85093)"

This reverts commit cd8843f87af2f04a85dda12b37738596cbf4cd5e.

Originally disabled to try to unstick the AMD build bot, didn't make a
difference after a week so it goes back in.

GitOrigin-RevId: 5cccc405e3981dfb97d5fee05b44a2ac6388191c
1 file changed