Update publish.yml

Python 3.10 was [being recognized](actions/setup-python#160 (comment)) as 3.1 due to semver. Added strings to avoid this issue to fix pypi distribution.

.github/workflows/publish.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.10
+          python-version: '3.10'
 
       - name: Install dependencies
         run: |