Use `NODE_BINARY` from `.xcode.env` when running packager from Xcode (#34121)

Summary:
Before this change, during the "Start Packager" Xcode build step that runs the packager, `packager.sh` was using my system node version and not the one from `nvm` that is meant to be used with the project.

## Changelog

[iOS] [Fixed] - Use `NODE_BINARY` from `.xcode.env` when running packager from Xcode

Pull Request resolved: https://github.com/facebook/react-native/pull/34121

Test Plan: Perform a build using Xcode and confirm that the packager is using the correct version of node.

Reviewed By: cortinico

Differential Revision: D37746951

Pulled By: cipolleschi

fbshipit-source-id: de697c27fe86ce65e8e3646cb30309ecc7f6c247

scripts/launchPackager.command

@@ -10,6 +10,10 @@ clear
 
 THIS_DIR=$(cd -P "$(dirname "$(readlink "${BASH_SOURCE[0]}" || echo "${BASH_SOURCE[0]}")")" && pwd)
 
+export PODS_ROOT="$THIS_DIR/../../../ios/Pods"
+WITH_ENVIRONMENT="$THIS_DIR/xcode/with-environment.sh"
+source $WITH_ENVIRONMENT
+
 # export packager environment variables
 source "$THIS_DIR/.packager.env"