ci: fix target-branch for testing

Author: pomfrida

.github/workflows/release_please.yml

@@ -35,6 +35,7 @@ jobs:
       - uses: google-github-actions/release-please-action@v4
         id: release
         with:
+          target-branch: fre/release-please
           config-file: .github/release-please-config.json
           manifest-file: .github/release-please-manifest.json
           token: ${{ secrets.GITHUB_TOKEN }}