[PG, Neon] Rename Neon Auth schema

[pffigueiredo]

Description

This PR aims to fix an issue caused by Neon renaming the internal schema neon_identity to neon_auth.

FIX

• Renamed the pre-defined schema internally, from neon_identity to neon_auth.

NOTES

• Neon will be launching the Neon Auth feature in the upcoming days, so it would be nice if we could publish a patch with this in the next couple of days 🙏

Test Plan

Adapted existing tests to use neon_auth.

Subscribers

cc @davidgomes

Issue

Closes #4063

[AndriiSherman]

@pffigueiredo If someone is already using previous schemas, maybe we don't need remove them but instead mark them as deprecated and provide a brief explanation of why they were deprecated. This way, we allow time for migration while also enabling a fast release of this feature in a patch update

[pffigueiredo]

@pffigueiredo If someone is already using previous schemas, maybe we don't need remove them but instead mark them as deprecated and provide a brief explanation of why they were deprecated. This way, we allow time for migration while also enabling a fast release of this feature in a patch update

We probably don't need to be that cautious, since we already "broke" things on our end, as in, we renamed neon_identity in favor of neon_auth and it's already in production. 👀