trying to fix github macos runner

Author: infothrill

.github/workflows/tests.yml

@@ -18,6 +18,6 @@ jobs:
         run: |
           python3 --version
           python3 -m pip install --upgrade pip
-          pip3 install tox
+          pip3 install --break-system-packages tox
       - name: Test with tox
         run: tox -e py,style