Update the testing-script to use github actions (#44923)

Summary:
With the migration to GHA, we are updating the testing scripts to work with the new CI.

There are a bit of shenanigans due to:
* How GHA archives artifacts => they are all `.zip` files, so I had to play around with unzipping them
* GHA seems to create a different commit, like if it is forking the repo instead of using it. I think that it is how the checkout action works. *Note:* this might be a problem for the `Create React Native Release` workflow because it has to commit on the stable branch!
* Android is building only the simulator architecture when running from regular CI. The app is not configured to run only on that, so the RNTestProject was a failing because it was trying to build all the available architectures. It is an easy fix in the user project space when release testing.

## Changelog:
[Internal] - Update the testing script to work with the new CI

Pull Request resolved: https://github.com/facebook/react-native/pull/44923

Test Plan:
Tested locally.

* [iOS] RNTester - Hermes ✅
* [iOS] RNTester - JSC ✅
* [Android] RNTester - Hermes ✅
* [Android] RNTester - JSC ✅
* [iOS] RNTestProject - Hermes ✅  (The project is created correctly and it builds, crash at runtime for https://github.com/facebook/react-native/issues/44926)
* [iOS] RNTestProject - JSC ✅ (The project is created correctly and it builds, crash at runtime for https://github.com/facebook/react-native/issues/44926)
* [Android] RNTester - Hermes ✅ (Needed to build only the simulator architecture)
* [Android] RNTester - JSC ✅ (Needed to build only the simulator architecture)

Reviewed By: andrewdacenko

Differential Revision: D58528432

Pulled By: cipolleschi

fbshipit-source-id: 733065de4c532b13d8e95e2217f9aafd5a2ef8a0