Bump codecov/codecov-action from 1 to 2.1.0 (ko-build#614)

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 1 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@v1...v2.1.0)

---
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>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/test.yaml

@@ -20,4 +20,4 @@ jobs:
 
       - run: go test -coverprofile=coverage.txt -covermode=atomic -race ./...
 
-      - uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@v2.1.0