Run e2e tests only on main and on stable branches (#45706)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/45706

## 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
To avoid flakyness and costs, let's run E2E tests only on main and on stable branches

Changelog:
[Internal] - Exploration to integrate maestro

Reviewed By: blakef

Differential Revision: D60283204

fbshipit-source-id: 806cb8905cb269f18785158dcc5777ef10e0ef44