Remove reset_approvals_patch_id feature flag

What does this MR do and why?

The feature flag was rolled out on production for around a week now and no issues were found/reported related to it.

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 #426874 (closed)