Fix tag creation in deploy workflow

As commented in #905, an annotated tag needs a configured user.

.github/workflows/deploy.yml

@@ -43,5 +43,7 @@ jobs:
 
     - name: Push tag
       run: |
+        git config user.name "pytest bot"
+        git config user.email "pytestbot@gmail.com"
         git tag --annotate --message=v${{ github.event.inputs.version }} v${{ github.event.inputs.version }} ${{ github.sha }}
         git push origin v${{ github.event.inputs.version }}