Pin GHA runner to Ubuntu 22.04 #416

Job	Run time
sanity	11s
unittests	12s
bookworm, good, verbose=bloom / build debs	4m 1s
focal, broken, cont-on-err / build debs	3m 57s
jammy, good, verbose=true / build debs	4m 14s
focal, broken / build debs	2m 19s
jammy, good, timeout=3 / build debs	3m 16s
bookworm squash / deploy	15s
jammy push / deploy	15s
	18m 40s

Provide feedback