Fix conda CI

Signed-off-by: Cristian Le <cristian.le@mpsd.mpg.de>

.github/workflows/step_tests-conda.yml

@@ -40,7 +40,6 @@ jobs:
           auto-update-conda: true
           auto-activate-base: false
           activate-environment: jupytext-ci
-          python-version: 3.x
           channels: defaults,conda-forge
           environment-file: .ci/environment-ci.yml
           use-only-tar-bz2: true
@@ -62,14 +61,11 @@ jobs:
           python -m jupyterlab.browser_check
 
       - name: Test with pytest
-        # We use an explicit coverage file otherwise the
-        # codecov action below does not find it
-        run: pytest --cov . --cov-report xml:coverage.xml
+        run: pytest --cov
 
       - name: Upload coverage
         uses: codecov/codecov-action@v3
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           fail_ci_if_error: true
           verbose: true
-          files: coverage.xml