Merge pull request #206 from thtom/coverage_badge_python_version

ci: fix coverage badge python version

Author: grische

.github/workflows/coverage_badge.yml

@@ -17,6 +17,9 @@ jobs:
       - uses: actions/checkout@v5
         with:
           ref: ${{ github.head_ref }}
+      - uses: actions/setup-python@v6
+        with:
+          python-version: "3.x"
 
       - name: Install Poetry
         run: |