Fix: increase checks-discovery-timeout for Wait for Docker Build

The Merge and Push Manifest check isn't materialized until the
build-arch matrix completes (its `if` gates on a job output), which
routinely takes longer than the action's 60s discovery window,
causing the release workflow to bail before Docker builds finish.

.github/workflows/ci-release.yml

@@ -26,6 +26,7 @@ jobs:
           check-name: 'Merge and Push Manifest'
           repo-token: ${{ secrets.GITHUB_TOKEN }}
           wait-interval: 60
+          checks-discovery-timeout: 1800
   build-release:
     name: Build Release
     needs: wait-for-docker