Remove Build container images - discovery #529

Job	Run time
build-ceph	1m 56s
build	7m 9s
demo	3m 35s
discovery (container)	3m 43s
pytest (cli)	2m 13s
discovery (embedded)	8m 58s
ha (sanity)	3m 45s
pytest (state)	1m 54s
pytest (multi_gateway)	2m 25s
ha (state_transitions)	3m 32s
ha (state_transitions_both_gws)	4m 33s
pytest (server)	2m 13s
pytest (grpc)	3m 7s
ha (state_transitions_loop)	13m 5s
ha (state_transitions_rand_loop)	16m 14s
pytest (omap_lock)	39m 56s
ha (late_registration)	4m 1s
pytest (old_omap)	1m 40s
ha (late_registration_loop)	15m 39s
pytest (log_files)	3m 7s
pytest (nsid)	39m 57s
push-to-registry	1s
	3h 2m 43s

Provide feedback