ci: split release-please into independent release and PR creation steps

.github/workflows/release-please.yml

@@ -17,8 +17,37 @@ jobs:
       release-created: ${{ steps.release.outputs.release_created }}
 
     steps:
+      # Create any releases first, then create tags, and then optionally create any new PRs.
       - uses: googleapis/release-please-action@16a9c90856f42705d54a6fda1823352bdc62cf38 # v4.4.0
         id: release
+        with:
+          skip-github-pull-request: true
+
+      # Need the repository content to be able to create and push a tag.
+      - uses: actions/checkout@v4
+        if: ${{ steps.release.outputs.release_created == 'true' }}
+
+      - name: Create release tag
+        if: ${{ steps.release.outputs.release_created == 'true' }}
+        env:
+          TAG_NAME: ${{ steps.release.outputs.tag_name }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          if gh api "repos/${{ github.repository }}/git/ref/tags/${TAG_NAME}" >/dev/null 2>&1; then
+            echo "Tag ${TAG_NAME} already exists, skipping creation."
+          else
+            echo "Creating tag ${TAG_NAME}."
+            git config user.name "github-actions[bot]"
+            git config user.email "github-actions[bot]@users.noreply.github.com"
+            git tag "${TAG_NAME}"
+            git push origin "${TAG_NAME}"
+          fi
+
+      - uses: googleapis/release-please-action@16a9c90856f42705d54a6fda1823352bdc62cf38 # v4.4.0
+        if: ${{ steps.release.outputs.release_created != 'true' }}
+        id: release-prs
+        with:
+          skip-github-release: true
 
   build-ruby-gem:
     needs: ["release-package"]