Bump codecov/codecov-action from v1.0.14 to v1.0.15

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from v1.0.14 to v1.0.15.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Commits](codecov/codecov-action@v1.0.14...239febf)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/tests.yaml

@@ -36,4 +36,4 @@ jobs:
           poetry run
           pytest --cov-config=pyproject.toml --cov=./ --cov-report=xml
       - name: Upload coverage to Codecov
-        uses: codecov/[email protected].14
+        uses: codecov/[email protected].15