Add Codecov Test Analytics (pydantic#1684)

Author: ajay-sentry

.github/workflows/ci.yml

@@ -42,7 +42,7 @@ jobs:
 
       - run: uv pip freeze
 
-      - run: uv run coverage run -m pytest
+      - run: uv run coverage run -m pytest --junitxml=junit.xml -o junit_family=legacy
 
       - run: ls -lha
       - run: uv run coverage xml
@@ -55,6 +55,10 @@ jobs:
         with:
           files: codecov.json
 
+      - uses: codecov/test-results-action@v1
+
+  # See https://github.com/PyO3/pyo3/discussions/2781
+  # tests intermittently segfault with pypy and cpython 3.7 when using `coverage run ...`, hence separate job
   test-python:
     name: test ${{ matrix.python-version }}
     strategy: