Prevent exporting internal objects of codegen (#51990)

Summary:
Pull Request resolved: #51990

In this diff I'm limiting visibility of internal objects of codegen, these objects are being exported but they are unused, let's avoid exporting them

changelog: [internal] internal

Reviewed By: christophpurrer

Differential Revision: D76470809

fbshipit-source-id: 0e168558d2d3211ab5a3a3de05e2495d7c1ae4f5

Author: mdvacca

packages/react-native-codegen/src/generators/RNCodegen.js

@@ -245,8 +245,6 @@ function checkOrWriteFiles(
 
 module.exports = {
   allGenerators: ALL_GENERATORS,
-  libraryGenerators: LIBRARY_GENERATORS,
-  schemaGenerators: SCHEMAS_GENERATORS,
 
   generate(
     {