fix: improve token handling in version bump workflow

.github/workflows/bump-version.yml

@@ -24,8 +24,10 @@ jobs:
           ref: ${{ github.event.pull_request.base.ref }}
           # fetch-depth 2 so HEAD~1 resolves to the pre-merge master commit
           fetch-depth: 2
-          # Use a PAT so the pushed bump commit can trigger deploy.yml
-          token: ${{ secrets.RELEASE_BOT_TOKEN }}
+          # Use a PAT so the pushed bump commit can trigger deploy.yml.
+          # Falls back to github.token if RELEASE_BOT_TOKEN is not configured
+          # (note: pushes with github.token won't re-trigger deploy.yml).
+          token: ${{ secrets.RELEASE_BOT_TOKEN || github.token }}
 
       - name: Set up Node
         uses: actions/setup-node@v6