CI: Fix target forlder for docs publish

Author: snowman2

.github/workflows/build_docs.yaml

@@ -50,7 +50,7 @@ jobs:
           branch: gh-pages
           folder: docs/_build/
           clean: false
-          target-folder: ${{ github.ref }}
+          target-folder: ${{ github.ref_name }}
 
       - name: Deploy 🚀
         uses: JamesIves/github-pages-deploy-action@v4