scrubber: add `scan-metadata` and hook into integration tests #12197

Job	Run time
check-codestyle-rust	7m 43s
build-neon (debug)	6m 45s
build-neon (release)	5m 44s
check-codestyle-python	26s
tag	41s
trigger-custom-extensions-build-and-wait	1m 4s
compute-tools-image	3m 47s
neon-image	9m 3s
compute-node-image (v14)	16m 44s
compute-node-image (v15)	15m 30s
regress-tests (debug, v14)	13m 19s
regress-tests (debug, v15)	9m 8s
regress-tests (release, v14)	6m 3s
regress-tests (release, v15)	6m 6s
benchmarks	0s
vm-compute-node-image (v14)	1m 42s
vm-compute-node-image (v15)	1m 24s
test-images	2m 31s
coverage-report (debug)	4m 0s
promote-images	1m 18s
trigger-e2e-tests	7s
deploy	0s
promote-compatibility-data	0s
create-test-report	7m 5s
	2h 0m 10s

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