fix: add contents write permission to update-packages job (#3138)

The update-packages job needs to push tags to the repository but was
missing the required `permissions: contents: write`. This caused the
workflow to fail with a 403 error when trying to push the version tag.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <noreply@anthropic.com>

.github/workflows/release.yml

@@ -69,6 +69,8 @@ jobs:
     if: ${{ needs.create-metadata.outputs.npm_packages != '[]' || needs.create-metadata.outputs.pypi_packages != '[]' }}
     runs-on: ubuntu-latest
     environment: release
+    permissions:
+      contents: write
     outputs:
       changes_made: ${{ steps.commit.outputs.changes_made }}
     steps: