github: update to test with Go 1.18 (#5262)
github: update to test with Go 1.18 (#5262)


grpc/grpc-go,stanley-cheung/grpc-go,stanley-cheung/grpc-go,dfawley/grpc-go,grpc/grpc-go,dfawley/grpc-go,menghanl/grpc-go,menghanl/grpc-go