Bump minimum CodeQL version to 2.16.6 #581

Job	Run time
Upload debug artifacts after failure in analyze (stable-v2.20.3)	1m 49s
Upload debug artifacts after failure in analyze (nightly-latest)	2m 18s
Upload debug artifacts after failure in analyze (default)	2m 15s
Upload debug artifacts after failure in analyze (linked)	2m 7s
Download and check debug artifacts after failure in analyze	6s
	8m 35s

Provide feedback