ci: select the release gate when the shared path reader changes

`check:release` is the only thing that runs
`windows-package-source-closure.test.mjs`, which is now the only reader of
`release-windows-check.yml`'s filter, and it reaches it through
`workflow-pull-request-paths.mjs`. Without this the module could change and
the suite that depends on it would not run.

Author: Astro-Han

scripts/ci-test-plan.mjs

@@ -77,6 +77,9 @@ const RELEASE_CONTRACT_FILES = new Set([
   'scripts/windows-upgrade-baseline.json',
   'scripts/windows-package-source-closure.mjs',
   'scripts/windows-package-source-closure.test.mjs',
+  // Reads the filter that closure test compares against, and `check:release`
+  // is the only gate that runs it against `release-windows-check.yml`.
+  'scripts/workflow-pull-request-paths.mjs',
 ]);
 
 // What decides whether a build can read durable state an earlier release wrote.