[ci] Protect image building.
Before, it was possible that a user could accidentally change (and break) container images used for building ogs as happened here: !3246 (merged).
No only @bilke is allowed to (break)...
Before, it was possible that a user could accidentally change (and break) container images used for building ogs as happened here: !3246 (merged).
No only @bilke is allowed to (break)...