Revert "test: force the smoke gate to fail, to watch it block a publish"

The gate held. Run 5320, dispatched with the forced failure in place:

  build-web    success   (candidate published)
  build-ml     success
  build-agent  success
  smoke-web    FAILED
  promote      skipped
  run          failure

And the three channel tags did not move:

  fabledcurator        33d3d8332f74 -> 33d3d8332f74
  fabledcurator-ml     e94a5435cb45 -> e94a5435cb45
  fabledcurator-agent  bae27d34d811 -> bae27d34d811

So a refresh that breaks something now leaves :latest naming the build that
works, which is the property milestone 362 exists to establish. The rejected
candidate is still published under :refresh-candidate, so whoever reads the
red job on Monday can pull the exact image that failed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TTjbZZ6JirCMSaJzQV1RhA

.forgejo/workflows/build.yml

@@ -1215,17 +1215,6 @@ jobs:
           curl -fsS --max-time 5 "http://$WEB_IP:8080/api/health"
           echo
 
-          # >>> TEMPORARY — REVERTED IN THE NEXT COMMIT <<<
-          # Milestone 362's verification says the gate must be watched
-          # REJECTING a build before anyone can believe it is wired up. Every
-          # real check above passes right now, so the only way to see a
-          # rejection is to force one. What is under test here is the job
-          # dependency, not the assertions: does a failed smoke actually stop
-          # the promote, and does :latest stay where it was?
-          echo "smoke: FORCED FAILURE — verifying the gate blocks the promote" >&2
-          exit 1
-          # >>> END TEMPORARY <<<
-
           echo "smoke: all checks passed against $CANDIDATE"
 
   # Move the channel tags — the whole point of the gate.