explicitly tell coverage.py to use .coveragerc file for config

.github/workflows/build.yml

@@ -140,7 +140,7 @@ jobs:
     runs-on: ubuntu-20.04
     env:
       GITHUB_ACTIONS_PYTHON_VERSION: "3.10"
-      PYTEST_ADDOPTS: "-rsxX --durations=25 --fixture-durations=10 --junit-xml=pytest.xml --cov-report xml:coverage.xml --cov-report= --cov interhost --cov intrahost --cov ncbi --cov phylo"
+      PYTEST_ADDOPTS: "-rsxX --durations=25 --fixture-durations=10 --junit-xml=pytest.xml --cov-config=.coveragerc --cov-report xml:coverage.xml --cov-report= --cov interhost --cov intrahost --cov ncbi --cov phylo"
     steps:
       - name: checkout repository
         uses: actions/checkout@v4