Update archaic standard in comments.

Problem/Motivation

Follow up from 📌 Fix method comments in non tests for Drupal.Commenting.DocComment.ShortSingleLine Fixed

@xjm commented in the MR on core/modules/search/src/SearchPageListBuilder.php

I almost reworded this since this was another archaic standard, but there are still 44 of these left in core, including on the most important things like EntityFormInterface, so I've left it alone.

@quietone used git grep 'Form submission handler' | nl to find the instances.

Steps to reproduce

TBD

Proposed resolution

Update comments to agreed upon standard

Remaining tasks

Find all instances
Update comments
Review

User interface changes

NA

API changes

NA

Data model changes

NA

Release notes snippet