ci: Make a530's GLES3/31 fractional runs much more complete.

ci: Make a530's GLES3/31 fractional runs much more complete.

Now that we don't get scheduled to any 19mhz CPUs, the old GLES3 job went
from 12 minutes of deqp-runner runtime to 54s.  Increase how much of the
testsuite we cover in exchange, still keeping the runtime at 3-6 min
(compared to previous 10-17 min).  Since the tests we're running changed,
reset the xfails list.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5115>