Remove configure_sentry_in_application_settings feature flag

What does this MR do and why?

Remove configure_sentry_in_application_settings feature flag

This makes the sentry settings in the admin panel to appear by default

Screenshots or screen recordings

With the feature flags enabled:

With any of the feature flags disabled:

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

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 #344832 (closed)