Revert: Bump minimum Node.js version to v22.11 (prev LTS) (#55113)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/55113

Reverts https://github.com/facebook/react-native/pull/55038

Dropping v20 (still in LTS) causes friction with Expo's LTS policy, so we're restoring support for v20.19.

Changelog: [General][Added] Revert https://github.com/facebook/react-native/pull/55038

Reviewed By: shwanton

Differential Revision: D90467161

fbshipit-source-id: d876cf7869f11e04058f88239f553704e0706514