Add the `ENTERPRISE_REPOSITORY` env var to let user consume artifacts from their personal maven mirror (#52514)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/52514

As per title, this change add the `ENTERPRISE_REPOSITORY` env variable so that users can use their owm maven mirror to consume artifacts rather than the official url.

This is helpful as:
- we can reduce the traffic toward maven central
- companies can speed up their builds by relying on local/closer replicas

## Changelog:
[iOS][Added] - Add the `ENTERPRISE_REPOSITORY` env variable to cocopaods infra

Reviewed By: cortinico

Differential Revision: D78011424

fbshipit-source-id: 24b83b4866095d7fe3318362afc5075b99b146e7