ci: bump runner sizes (#23514)

Bumps the runners changed in 5544a60b6e to larger sizes.

.github/workflows/ci.yaml

@@ -1081,7 +1081,7 @@ jobs:
     needs:
       - changes
     if: (github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/heads/release/')) && needs.changes.outputs.docs-only == 'false' && !github.event.pull_request.head.repo.fork
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-latest-16-cores
     permissions:
       # Necessary to push docker images to ghcr.io.
       packages: write

.github/workflows/release.yaml

@@ -61,7 +61,7 @@ jobs:
   release:
     name: Build and publish
     needs: [check-perms]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-latest-16-cores
     permissions:
       # Required to publish a release
       contents: write