ci: fix syntax for actions/checkout@v2

Author: IATkachenko

.github/workflows/release.yml

@@ -57,7 +57,8 @@ jobs:
     - name: checkout
       uses: actions/checkout@v2
       id: checkout
-      ref: ${{ needs.changes.outputs.tag }}
+      with:
+        ref: ${{ needs.changes.outputs.tag }}
 
     - name: Prepare python for publish
       uses: actions/setup-python@v2