ci: drop the k3s ctr smoke test, impossible on the containerized runner

The step ran `sudo k3s ctr images pull` / `ctr run` against the host's
containerd. That worked when the runner was the Arch host; since it was
containerized (infra#233) the image has no sudo, no ctr and no containerd
socket, so the step fails with `sudo: command not found`. It only
surfaced now because the buildah wall (infra#241) killed the job before
this step ever ran.

The deploy job's `Verify rollout` and `Confirm pod running new image`
assert the same property against the real workload rather than a 5s
throwaway container, which is why tapir dropped its smoke test under the
same issue.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011PL5XcG68SvQqz3vGVbWbf

.gitea/workflows/cd.yml

@@ -106,17 +106,13 @@ jobs:
           fi
           echo "✓ Image pushed to ${REF}"
 
-      - name: Smoke test
-        run: |
-          REGISTRY="localhost:5000"
-          REF="${REGISTRY}/${{ env.IMAGE }}:${{ steps.meta.outputs.sha-tag }}"
-          CNAME="smoke-${{ steps.meta.outputs.sha-tag }}"
-          sudo k3s ctr images pull --plain-http ${REF}
-          OUTPUT=$(timeout 5 sudo k3s ctr run --rm ${REF} ${CNAME} /gitea-mcp 2>&1 || true)
-          sudo k3s ctr containers delete ${CNAME} 2>/dev/null || true
-          echo "$OUTPUT" | grep -q "gitea-mcp" \
-            && echo "✓ Smoke test passed" \
-            || echo "⚠ Smoke test inconclusive: $OUTPUT"
+      # No smoke test here. The old one ran `sudo k3s ctr run` against the host's
+      # containerd: written for the Arch host runner, impossible in the
+      # containerized runner (infra#233) which has no sudo, no ctr and no
+      # containerd socket -- it failed with `sudo: command not found` the moment
+      # infra#241's buildctl migration let the build reach it. The deploy job's
+      # `Verify rollout` + `Confirm pod running new image` cover the same ground
+      # more strongly, which is why tapir dropped its smoke test too (infra#241).
 
   # ── 3. Deploy via infra repo + Flux ─────────────────────────────────────────
   deploy: