fix(hydra-gates): vendor manifest schema 2.171.0 and run the sync PR's required checks

.github/workflows/hydra-gates-schema-sync.yml

@@ -70,6 +70,9 @@ on:
 permissions:
   contents: write
   pull-requests: write
+  # Needed to dispatch the required checks onto the sync branch; see the
+  # "Run the required checks" step.
+  actions: write
 
 concurrency:
   group: hydra-gates-schema-sync
@@ -194,6 +197,19 @@ jobs:
             --body-file pr-body.md)
           echo "${NEW_PR}"
 
+          # The `pull_request` runs of a PR opened with GITHUB_TOKEN wait for
+          # approval and start no job, so the three required checks on main
+          # never report and the sync PR sits BLOCKED until a human pushes to
+          # it. Measured 2026-11-03: #859 to #894 (2.126.0 to 2.171.0) were
+          # each opened, never checked (runs `action_required` or zero jobs),
+          # and closed by the next run, while the vendored copy stayed at
+          # 2.138.0. A workflow_dispatch fired with GITHUB_TOKEN runs without
+          # approval, and its check runs land on the branch's head commit,
+          # which is what the ruleset reads.
+          for WF in hydra-gates-package.yml quality-resolve-probe.yml; do
+            gh workflow run "${WF}" --ref "${BRANCH}"
+          done
+
           # An older sync PR left open is how the copy stayed behind: each run
           # opened a new branch and the previous one sat unmerged. Close the
           # ones this PR supersedes, so exactly one sync PR is open at a time.