Scripts: remove checked-in `debugger;` statements (#49289)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/49289

These snuck in, presumably accidentally, via https://github.com/facebook/react-native/pull/49164.

This interferes with running test suites with a debugger connected (e.g, when debugging Jest itself).

(Aside: we should probably enable [`eslint/no-debugger`](https://eslint.org/docs/latest/rules/no-debugger) to catch these)

Changelog: [Internal]

Reviewed By: hoxyq

Differential Revision: D69377992

fbshipit-source-id: 5d51d18be76f9b01852b2e5b7297b95452f36d55