chore(deps): update codecov/codecov-action action to v3 (#22)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/main.yml

@@ -55,7 +55,7 @@ jobs:
         run: flutter test --no-pub --coverage
 
       - name: Codecov Dart SDK
-        uses: codecov/codecov-action@v2
+        uses: codecov/codecov-action@v3
         with:
           flags: Dart-sdk
           directory: ./lib