Bump codecov/codecov-action from 2.1.0 to 3.1.0

Author: github-actions[bot]

.github/workflows/mutation-tests.yml

@@ -56,4 +56,4 @@ jobs:
         run: "make infection PHPUNIT_FLAGS=--coverage-clover=coverage.xml INFECTION_FLAGS=--logger-github"
 
       - name: "Upload Code Coverage"
-        uses: "codecov/codecov-action@v2.1.0"
+        uses: "codecov/codecov-action@v3.1.0"