Bump codecov/codecov-action from v1 to v2

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from v1 to v2.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/master/CHANGELOG.md)
- [Commits](codecov/codecov-action@v1...v2.0.2)

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

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -33,6 +33,6 @@ jobs:
           dotnet test --collect:"XPlat Code Coverage"
           dotnet tool restore
           dotnet tool run reportgenerator "-reports:**/coverage.cobertura.xml" "-targetdir:coverlet/reports" "-reporttypes:Cobertura"
-      - uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@v2
         with:
           name: unittests-${{ matrix.os }}