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/fileinit/desc.go b/internal/fileinit/desc.go
index 8854cab..a341d3c 100644
--- a/internal/fileinit/desc.go
+++ b/internal/fileinit/desc.go
@@ -13,14 +13,14 @@
 	"reflect"
 	"sync"
 
-	descopts "github.com/golang/protobuf/v2/internal/descopts"
-	pimpl "github.com/golang/protobuf/v2/internal/impl"
-	pragma "github.com/golang/protobuf/v2/internal/pragma"
-	pfmt "github.com/golang/protobuf/v2/internal/typefmt"
-	"github.com/golang/protobuf/v2/proto"
-	pref "github.com/golang/protobuf/v2/reflect/protoreflect"
-	preg "github.com/golang/protobuf/v2/reflect/protoregistry"
-	piface "github.com/golang/protobuf/v2/runtime/protoiface"
+	descopts "google.golang.org/protobuf/internal/descopts"
+	pimpl "google.golang.org/protobuf/internal/impl"
+	pragma "google.golang.org/protobuf/internal/pragma"
+	pfmt "google.golang.org/protobuf/internal/typefmt"
+	"google.golang.org/protobuf/proto"
+	pref "google.golang.org/protobuf/reflect/protoreflect"
+	preg "google.golang.org/protobuf/reflect/protoregistry"
+	piface "google.golang.org/protobuf/runtime/protoiface"
 )
 
 // FileBuilder construct a protoreflect.FileDescriptor from the