Bump codecov/codecov-action from 2.0.3 to 2.1.0

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 2.0.3 to 2.1.0.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/master/CHANGELOG.md)
- [Commits](codecov/codecov-action@v2.0.3...v2.1.0)

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

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

Author: dependabot[bot]

.github/workflows/mutation-tests.yml

@@ -56,4 +56,4 @@ jobs:
         run: "make infection PHPUNIT_FLAGS=--coverage-clover=coverage.xml"
 
       - name: "Upload Code Coverage"
-        uses: "codecov/codecov-action@v2.0.3"
+        uses: "codecov/codecov-action@v2.1.0"