Remove support for my-hacks.php

For the last 10 years, my-hacks has been deprecated and has been throwing a deprecation notice. For the last six years, you haven't been able to enable my-hacks.php in the admin UI. That should be enough time to give developers notice. Plugins and themes seem like they might have staying power.

Fixes #33741
Props bobbingwide



git-svn-id: https://develop.svn.wordpress.org/trunk@34291 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/schema.php

@@ -412,7 +412,6 @@ function populate_options() {
 	'moderation_notify' => 1,
 	'permalink_structure' => '',
 	'gzipcompression' => 0,
-	'hack_file' => 0,
 	'blog_charset' => 'UTF-8',
 	'moderation_keys' => '',
 	'active_plugins' => array(),