Code Insights: Remove `allowSiteSettingsEdits` checks
Created by: vovakulikov
Closes https://github.com/sourcegraph/sourcegraph/issues/29482
Context
Code Insights can work with two different backends (data providers)
- Setting cascade (deprecated way)
- Real GQL backend (currently primary backend)
So in the setting cascade world, it might be a case when setting cascade is locked for writing operations and we have a special field in the setting cascade about this case allowSiteSettingsEdits
.
This PR removes checks by that field in the dashboard creation and edit UI. Because it's no anymore relevant since we use the new GQL based backend.
It's safe to just delete this from UI for both API because for setting cascade UI we have an error message banner in forms in case if some operation is forbidden.