Update Overlay (#1)

# Changes
Defining regions and removing non core API endpoints from generated SDK

# Motivation
https://vanta-team-j1bu05uk.atlassian.net/browse/PEX-4050

# Testing
Going to chat with Speakeasy rep to verify that there were not hiccups.
I used the studio to verify it compiles: https://overlay.speakeasy.com/

# Deployment
Rollbackable

Author: dangitschris