Remove the feature flag npm_group_level_endpoints

Context

The feature flag npm_group_level_endpoints was enabled globally on 24 May: link (internal)

What does this MR do and why?

This MR removes the feature flag npm_group_level_endpoints

Screenshots or screen recordings

No.

How to set up and validate locally

No.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #409476 (closed)