Bump ruby to 2.7.5 (#33485)

Summary:
This bumps ruby to the latest 2.7.x versions which includes bug fixes and 3 CVEs (https://www.ruby-lang.org/en/news/2021/11/24/ruby-2-7-5-released/)

## Changelog

[iOS] [Changed] - Bump ruby to 2.7.5

Pull Request resolved: https://github.com/facebook/react-native/pull/33485

Test Plan: no test plan, should just pass tests.

Reviewed By: cortinico

Differential Revision: D35116757

Pulled By: GijsWeterings

fbshipit-source-id: a8e96bfcc6086b70dac21aee24bae46fe6b072bb