ci: Disable navi21-valve jobs for now, minor xfail updates
All 3 runners are having truoble with logs looping like:
+4.865s: Completed setup of the infrastructure, after 0:00:04.554475 s
+4.873s: Setting up the boot configuration
+4.873s: Power up the machine, enforcing 30.0 seconds of down time
+31.352s: Boot the machine
+332.459s: Hit the timeout <Timeout first_console_activity: value=0:05:00, retries=1/3> --> Try again!
Edited by Emma Anholt