tests: don't limit the number of pytest workers (#5441)

We used to do this because of gitpython leaks.

.github/workflows/tests.yaml

@@ -80,7 +80,7 @@ jobs:
         mkdir -p scripts/ci
         echo "$GS_CREDS_JSON" > scripts/ci/gcp-creds.json
     - name: run tests
-      run: python -m tests --all --cov-report=xml --cov-report=term --tap-combined
+      run: python -m tests --all --cov-report=xml --cov-report=term --tap-combined -n=4
     - name: upload coverage report
       uses: codecov/[email protected]
       with:

tests/__main__.py

@@ -16,5 +16,5 @@ os.putenv("DVC_HOME", REPO_ROOT)
 
 params = " ".join(sys.argv[1:])
 
-cmd = "pytest -v -n=4 --cov=dvc --durations=0 {params}".format(params=params)
+cmd = f"pytest -v -n=auto --dist loadscope --cov=dvc --durations=0 {params}"
 check_call(cmd, shell=True)