Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/33674
## Issue
In D35317070 (0480f56c5b) we introduced a way to configuring the Xcode environment via he `.xcode.env`, falling back to the old `find-node-for-xcode.sh` behavior in case of a misconfiguration.
Unfortunately, there were an issue with the new architecture for which the pods were not able to locate the `find-node-for-xcode.sh`, crashing while building the new architecture.
## Solution
This Diff solves the issue in two steps:
1. it exposes to the project the REACT_NATIVE_PATH like Android does here: D35451821 (f8d7e0a968)
2. it leverages this new variables to reach the script
## Changelog
[iOS][Changed] - Fixed the fallback behavior when the `.xcode.env` file is missing, actually using the old `find-node-for-xcode.sh` script
Reviewed By: dmitryrykun
Differential Revision: D35779165
fbshipit-source-id: 393ef9a0b98d32d9cf226f7d109fdefd772e5120