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/internal/cmd/pbdump/pbdump_test.go b/internal/cmd/pbdump/pbdump_test.go
index 9e50ec4..57ec1b5 100644
--- a/internal/cmd/pbdump/pbdump_test.go
+++ b/internal/cmd/pbdump/pbdump_test.go
@@ -12,8 +12,8 @@
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 
-	ptype "github.com/golang/protobuf/v2/internal/prototype"
-	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
+	ptype "google.golang.org/protobuf/internal/prototype"
+	pref "google.golang.org/protobuf/reflect/protoreflect"
 )
 
 func TestFields(t *testing.T) {