Remove report-app-size (#45483)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/45483

We don't really use this functionality and is getting harder to migrate to GHA,
hence I'm removing it.

Changelog:
[Internal] [Changed] - Remove report-app-size

Reviewed By: cipolleschi

Differential Revision: D59822862

fbshipit-source-id: 2d082454aea3b3c5863bd34556a23c2fc847f841