Fix version release tag message being "" instead of empty

Little hacky but no variations of `--message` and `""` seemed to work

This simply a bug in EndBug/add-and-commit action's argument parsing,
the original one is ofc a completely valid Git command.

Author: ruohola

.github/workflows/cd.yml

@@ -56,7 +56,7 @@ jobs:
         with:
           add: '["pyproject.toml", "CHANGELOG.md"]'
           message: 'Release ${{ github.event.inputs.version }}'
-          tag: 'v${{ github.event.inputs.version }} --annotate --message=""'
+          tag: 'v${{ github.event.inputs.version }} --annotate --file <(true)'
           default_author: github_actions
 
       - name: "Create a GitHub release"