fix: pass source flag to codegen cli when possible

[atlj]

Summary

facebook/react-native@98b8f17 adds support for --source flag in npx @react-native-community/cli codegen. With this flag, we can opt out of our patch. With this PR, bob checks if this flag is supported and uses it if it is.

Test plan

1. Generate a library with a React Native version that supports --source. (The baseline is [email protected]).
2. Run yarn prepare
3. Make sure the command runs with no errors
4. Check the ios/generated and make sure there are no .podspec files.

[Copilot]

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

packages/react-native-builder-bob/src/targets/codegen/patches/removeCodegenAppLevelCode.ts:80

• Consider adding error handling to getCodegenCLISourceSupport to manage cases where the spawn call fails, which could otherwise lead to unhandled promise rejections.

const codegenCLIHelpOutput = await spawn('npx', ['@react-native-community/cli', 'codegen', '--help']);