Generate the RCTModulesConformingToProtocolsProvider only for react-n…

…ative core (#43046)

Summary:
Pull Request resolved: #43046

This fixes a problem where RCTModulesConformingToProtocolsProvider was generated also in Library space.

## Changelog:
[iOS][Fixed] - Generate the RCTModulesConformingToProtocolsProvider only once in user space

## Facebook
See comment [here](https://www.internalfb.com/diff/D53441411?dst_version_fbid=750944970297544&transaction_fbid=719673583317629)

Reviewed By: dmytrorykun

Differential Revision: D53807045

fbshipit-source-id: 2c4a15c3c7943cfcc1f5ea5dd5ab47c3a31e6596

packages/react-native/scripts/codegen/generate-artifacts-executor.js

@@ -676,9 +676,9 @@ function execute(projectRoot, targetPlatform, baseOutputPath) {
         );
 
         createComponentProvider(schemas, supportedApplePlatforms);
+        generateCustomURLHandlers(libraries, outputPath);
       }
 
-      generateCustomURLHandlers(libraries, outputPath);
       cleanupEmptyFilesAndFolders(outputPath);
     }
   } catch (err) {