CI: run pytest without arguments to avoid stdlib distutils being impo…

…rted

distutils currently doesn't support pytest collection that doesn't
start at least at the distutils dir or above (and not distutils/tests)
since it requires the local distutils being imported before the tests are run,
otherwise the stdlib distutils takes precedence.

Adjust the pytest call to not pass a path to work around this.

Since pytest currently fails to skip collecting venvs with mingw python
(see pytest-dev/pytest#12544) move the venv
to /tmp instead.

.github/workflows/main.yml

@@ -146,8 +146,8 @@ jobs:
         run: |
           export VIRTUALENV_NO_SETUPTOOLS=1
 
-          python -m virtualenv venv
-          source venv/bin/activate
+          python -m virtualenv /tmp/venv
+          source /tmp/venv/bin/activate
 
           # python-ruff doesn't work without rust
           sed -i '/pytest-ruff/d' pyproject.toml
@@ -156,8 +156,8 @@ jobs:
       - name: Run tests
         shell: msys2 {0}
         run: |
-          source venv/bin/activate
-          pytest distutils/tests
+          source /tmp/venv/bin/activate
+          pytest
 
   ci_setuptools:
     # Integration testing with setuptools