Add CodeCov to pull requests

.github/workflows/pull_request_tests.yml

@@ -21,7 +21,8 @@ jobs:
         python -m pip install ".[dev]"
     - name: Run pytest
       run: |
-        python -m pytest -v --disable-warnings tests
+        python -m pytest -v --disable-warnings --cov=./ --cov-report=xml:coverage.xml tests
+        cat coverage.xml
   mypy:
     runs-on: ubuntu-latest
     name: "mypy"
@@ -39,3 +40,15 @@ jobs:
           src: "src"
           pip_install_command: "pip install -e .[dev]"
           python_version: "3.11"
+  codecov:
+    runs-on: ubuntu-latest
+    name: codecov
+    steps:
+      - uses: codecov/[email protected]
+        with:
+          file: ./coverage.xml
+          flags: unittests
+          env_vars: OS,PYTHON
+          name: codecov-umbrella
+          fail_ci_if_error: false
+          verbose: true