all: change module to google.golang.org/protobuf

Temporarily remove go.mod, since we can't generate an accurate one until
the corresponding v1 change is submitted.

Change-Id: I1e1ad97f2b455e33f61ffaeb8676289795e47e72
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177000
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/protogen/protogen_test.go b/protogen/protogen_test.go
index f3852d7..d4da172 100644
--- a/protogen/protogen_test.go
+++ b/protogen/protogen_test.go
@@ -9,12 +9,12 @@
 	"fmt"
 	"testing"
 
-	"github.com/golang/protobuf/v2/internal/scalar"
-	"github.com/golang/protobuf/v2/reflect/protoreflect"
 	"github.com/google/go-cmp/cmp"
+	"google.golang.org/protobuf/internal/scalar"
+	"google.golang.org/protobuf/reflect/protoreflect"
 
-	descriptorpb "github.com/golang/protobuf/v2/types/descriptor"
-	pluginpb "github.com/golang/protobuf/v2/types/plugin"
+	descriptorpb "google.golang.org/protobuf/types/descriptor"
+	pluginpb "google.golang.org/protobuf/types/plugin"
 )
 
 func TestPluginParameters(t *testing.T) {