examples/grpc-e2e-tests/tests doesn't build from `go build .`

Issue tracking that examples/grpc-e2e-tests/tests seems to not build currently:

$ cd examples/grpc-e2e-tests/tests; go build .
client.go:11:2: github.com/GoogleContainerTools/skaffold/examples/grpc-e2e-tests/service@v0.0.0-00010101000000-000000000000: missing go.sum entry; to add it:
    go mod download github.com/GoogleContainerTools/skaffold/examples/grpc-e2e-tests/service
$ go mod tidy                                                        1 ✘  1.19.2  
github.com/GoogleContainerTools/skaffold/v2/integration/examples/grpc-e2e-tests/tests imports
    github.com/GoogleContainerTools/skaffold/v2/examples/grpc-e2e-tests/service/proto: github.com/GoogleContainerTools/skaffold/examples/grpc-e2e-tests/service@v0.0.0-00010101000000-000000000000: invalid version: unknown revision 000000000000
github.com/GoogleContainerTools/skaffold/v2/integration/examples/grpc-e2e-tests/tests tested by
    github.com/GoogleContainerTools/skaffold/v2/integration/examples/grpc-e2e-tests/tests.test imports
    github.com/GoogleContainerTools/skaffold/v2/integration/examples/grpc-e2e-tests/service/proto: github.com/GoogleContainerTools/skaffold/examples/grpc-e2e-tests/service@v0.0.0-00010101000000-000000000000: invalid version: unknown revision 000000000000
github.com/GoogleContainerTools/skaffold/v2/integration/examples/grpc-e2e-tests/tests tested by
    github.com/GoogleContainerTools/skaffold/v2/integration/examples/grpc-e2e-tests/tests.test imports
    github.com/onsi/gomega imports
    github.com/onsi/gomega/matchers imports
    gopkg.in/yaml.v3 tested by
    gopkg.in/yaml.v3.test imports
    gopkg.in/check.v1: github.com/GoogleContainerTools/skaffold/examples/grpc-e2e-tests/service@v0.0.0-00010101000000-000000000000: invalid version: unknown revision 000000000000

NOTE: This is not a huge issue as running skaffold build from examples/grpc-e2e-tests does work as this tests dir is not used. As the tests dir is not used, it might make sense to delete it outright.

Potential Solutions:

fix examples/grpc-e2e-tests/tests deps, source, etc. so that go build . works
OR remove the examples/grpc-e2e-tests/tests as it is unused with respect to skaffold currently

GoogleContainerTools / skaffold

examples/grpc-e2e-tests/tests doesn't build from `go build .` #8474