[9.18] Add CodeQL GitHub Action
Replace the decommissioned LGTM service with CodeQL GitHub action.
(cherry picked from commit 77abe612)
Backport of MR !7393 (merged)
Edited by Ondřej Surý
Replace the decommissioned LGTM service with CodeQL GitHub action.
(cherry picked from commit 77abe612)
Backport of MR !7393 (merged)