Fix copy symbol files in RNDeps precompile (#53353)

Summary:
Symbol files wasn't copied correctly when building - as with bundles we did overwrite the files and ended up with only the last symbol file.

This commit fixes this by mapping the framework build folder architecture type to the xcframework slices creating the correct file structure under the Symbols folder.

- Each slice gets a folder with the architecture name under Symbols containing the dSym folder for that slice
- Refactored getting correct architecture folder into a separate function.
- Refactored target folder lookup in copyBundles
- Removed unused async modifier on function

## Changelog:

[IOS] [FIXED] - Fixed how we copy and build the Symbols folder when precompiling ReactNativeDependencies

Pull Request resolved: https://github.com/facebook/react-native/pull/53353

Test Plan: Run nightlies and verify that ReactNativeDependencies.framework.dSym files contains symbol files for all architectures.

Reviewed By: cortinico

Differential Revision: D80692019

Pulled By: cipolleschi

fbshipit-source-id: 77983bc29d1965edf3bc0fcbd9cb3177071991d3