Bump codecov/codecov-action from 3.1.5 to 3.1.6

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 3.1.5 to 3.1.6.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](codecov/codecov-action@v3.1.5...v3.1.6)

---
updated-dependencies:
- dependency-name: codecov/codecov-action
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/main.yml

@@ -36,6 +36,6 @@ jobs:
       - name: Run tests
         run: tox
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v3.1.5
+        uses: codecov/codecov-action@v3.1.6
         with:
           env_vars: PYTHON