Adjust #598 to only create a PR rather than pushing changes to main branch (#1162)

This pull request resolves the execution error of #598 CI job. The job
pushes the changes directly to the main branch. However, our branch
policies do not allow bypassing required checks, so it always fails.
This pull request changes its behavior just to create a pull request and
then ask humans to review (actually you don't need to check translation
results though) and merge it.

Author: seratch

.github/workflows/update-docs.yml

@@ -15,6 +15,7 @@ on:
 
 jobs:
   update-docs:
+    if: "!contains(github.event.head_commit.message, 'Update all translated document pages')"
     name: Build and Push Translated Docs
     runs-on: ubuntu-latest
     timeout-minutes: 20
@@ -34,14 +35,26 @@ jobs:
       - name: Build full docs
         run: make build-full-docs
 
-      - name: Commit and push changes
+      - name: Commit changes
+        id: commit
         run: |
           git config user.name "github-actions[bot]"
           git config user.email "github-actions[bot]@users.noreply.github.com"
           git add docs/
           if [ -n "$(git status --porcelain)" ]; then
             git commit -m "Update all translated document pages"
-            git push
+            echo "committed=true" >> "$GITHUB_OUTPUT"
           else
             echo "No changes to commit"
+            echo "committed=false" >> "$GITHUB_OUTPUT"
           fi
+
+      - name: Create Pull Request
+        if: steps.commit.outputs.committed == 'true'
+        uses: peter-evans/create-pull-request@v6
+        with:
+          commit-message: "Update all translated document pages"
+          title: "Update all translated document pages"
+          body: "Automated update of translated documentation"
+          branch: update-translated-docs-${{ github.run_id }}
+          delete-branch: true