Summary:
## Context
Running manual tests when preparing a release, it's time consuming.
We have to do the cherry picks, wait for CI to finish, and then manually test 8 configurations.
Maestro is a tool that allow us to run E2E tests automatically, and we can wire it to CI.
## Change
Add a test flow for RNTester
## Changelog:
[Internal] - Exploration to integrate maestro
Pull Request resolved: https://github.com/facebook/react-native/pull/45574
Test Plan: GHA
Reviewed By: blakef
Differential Revision: D60282147
Pulled By: cipolleschi
fbshipit-source-id: 4ecba84f0b2c7186de2bb9938043e73a0bd9a6bd