selftests/bpf: test_xsk: Isolate non-CI tests

Following tests won't fit in the CI:
- XDP_ADJUST_TAIL_* and SEND_RECEIVE_9K_PACKETS because of their
  flakyness
- UNALIGNED_* because they depend on huge page allocations
- *_RING_SIZE because they depend on HW rings
- TEARDOWN because it's too long

Remove these tests from the nominal tests table so they won't be
run by the CI in upcoming patch.
Create a skip_ci_tests table to hold them.
Use this skip_ci table in xskxceiver.c to keep all the tests available
from the test_xsk.sh script.

Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet@bootlin.com>
Link: https://lore.kernel.org/r/20251031-xsk-v7-14-39fe486593a3@bootlin.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2 files changed