Remove the trigger-react-native-release to use the GHA workflow_dispatch UI (#44898)

Summary:
This change removes the need for the trigger-react-native-release.js script.
Thanks to the migration to Github Actions, we can now leverage the GHA workflow UI to trigger a Prepare Release job that creates a github tag that will spin a new release.

The pro of this approach are:
- less code to maintain: instead of a complex trigger release scripts, we only have to maintain two very straightforward scripts for the CI
- easier to trigger a release: instead of running a script, we can now just use the GH UI

The `trigger-react-native-release` script was doing the following steps:
- check that we are in the release branch ==> Already implemented in the GHA workflow
- Gets the branch name (not needed) ==> the job will automatically run on the stable branch
- Check for unsent changes (not needed) ==> we are not in a local environment
- get the gh token (not needed) ==> You need to be logged in GH and have write access to the repo
- get the version ==> provided as a parameter
- fails if the tag is already there ==> Functionality added in the workflow
- Parse and validate the version ==> Functionality added to the action prepare-release action + the JS Script
- Compute the npmTag ==> Functionality added to the action prepare-release action + the JS Script
- trigger the release workflow ==> The GH UI does that for us

## Changelog:
[Internal] - Remove the trigger-react-native-release.js

Pull Request resolved: https://github.com/facebook/react-native/pull/44898

Test Plan: Testing in Production!

Reviewed By: cortinico, huntie

Differential Revision: D58461470

Pulled By: cipolleschi

fbshipit-source-id: 32bb0ee91370c9483a29e2ca2e18e24557d5fd53