chore: add coverage reporting to pytest

Add `pytest-cov` to `requirements-dev.txt` and enable coverage
reporting in `run_tests.py` by including `--cov` and `--cov-
report=xml` options. This provides insight into code coverage,
helping to identify areas lacking test coverage.

Author: DefinitelyADev

.github/workflows/ci.yml

@@ -37,10 +37,11 @@ jobs:
         python run_tests.py
 
     - name: Upload coverage to Codecov
-      if: matrix.python-version == '3.11'
+      if: matrix.python-version == '3.12'
       uses: codecov/codecov-action@v5
       with:
         files: ./coverage.xml
+        token: ${{ secrets.CODECOV_TOKEN }}
         fail_ci_if_error: false
 
   validate:

requirements-dev.txt

@@ -1,6 +1,7 @@
 # Development dependencies
 pytest>=7.0.0
 pytest-asyncio>=0.20.3
+pytest-cov
 pytest-homeassistant-custom-component>=0.13.0
 
 # Home Assistant testing

run_tests.py

@@ -22,9 +22,10 @@ def run_tests():
             sys.executable,
             "-m",
             "pytest",
-            "custom_components/custom_areas/tests/",
             "-v",
-            "--tb=short",
+            "--cov",
+            "--cov-branch",
+            "--cov-report=xml",
         ],
         capture_output=True,
         text=True,