Standardized CI gate on the org-wide "Required checks pass" check

Branch protection previously required the check named "All tests pass",
which couples the ruleset to this repo's particular CI job naming. The
org is standardizing every repository on a single stable aggregator
check named "Required checks pass", so rulesets can require one
context everywhere regardless of how each repo's test matrix evolves.

This renames the existing aggregator job (id and name only — needs
coverage, trigger conditions, and the failure/cancelled verification
step are unchanged). The branch ruleset is being updated in the same
pass to require the new check name, so this PR must go green on the
new gate before merging.

Author: aileen

.github/workflows/test.yml

@@ -32,8 +32,8 @@ jobs:
 
       - run: pnpm exec gscan --fatal --verbose .
 
-  all-tests-pass:
-    name: All tests pass
+  required-checks-pass:
+    name: Required checks pass
     if: always()
     needs: [test]
     runs-on: ubuntu-latest