build: add sync-fork action [skip ci]

.github/workflows/sync-fork.yml

@@ -18,8 +18,9 @@ jobs:
       - name: fetch and push tags
         shell: bash
         run: |
-          git fetch --tags --prune --prune-tags origin feature/blabla
           git fetch --tags https://github.com/dagger/dagger
           git push --tags
+        env:
+          BRANCH_NAME: ${{ github.ref_name }}