Update codecov/codecov-action action to v7

Author: renovate[bot]

.github/workflows/tests.yml

@@ -75,6 +75,6 @@ jobs:
         run: |
           pytest --cov=./
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v7
         with:
           name: codecov-umbrella