Fix the publish workflow (#564)

Author: shatakshiiii

.github/workflows/tox.yml

@@ -127,6 +127,8 @@ jobs:
       - name: Create a new branch, update the file and push the branch
         if: github.event_name == 'release' && github.event.action == 'published'
         run: |
+          git config --global user.name "ansibuddy"
+          git config --global user.email "[email protected]"
           cd ansible-devspaces-demo
           git checkout -b update-devspaces-image-${{ github.event.release.tag_name }}
           export SHA=$(docker manifest inspect -v ghcr.io/ansible/ansible-devspaces:latest | jq -r '[.Descriptor.digest][0]')