Bump Podfile.lock automatically (#50345)

Summary:
This workflow bumps the Podfile.lock automatically when a new release happens.
I decided not to use a js script in this case because all the commands are bash commands for git or cocoapods, therefore wrapping them all in a JS file would have added little to no benefit and only overheads.

## Changelog:
[Internal] - Bumps podfile.lock automatically

Pull Request resolved: https://github.com/facebook/react-native/pull/50345

Test Plan:
GHA - tested as a separate workflow first, hardcoding the latest RC
https://github.com/facebook/react-native/actions/runs/14127895380/job/39581024861?pr=50345

The flow correctly fails as the Podfile.lock has already been bumped in the release branch.

Reviewed By: fabriziocucci

Differential Revision: D72050261

Pulled By: cipolleschi

fbshipit-source-id: 5c0666e80b037319c365fcf4d52e8e367c3445ea