update 'upload-artifact' Action

Author: Mrcubix

.github/workflows/sphinx.yml

@@ -28,7 +28,7 @@ jobs:
           sphinx-build . _build
 
       - name: Upload docs
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@main
         with:
           name: HTML Docs
           path: _build/html