Removes the automatic addition of `rel="noopener noreferrer"` from links targeting a new tab or window, `target='_blank'`. Since this was introduced, supported browsers have changed their security policies and no longer allow the opened link to have JavaScript access to the previous tab.
Deprecates:
* `wp_targeted_link_rel()`
* `wp_targeted_link_rel_callback()`
* `wp_init_targeted_link_rel_filters()`: converted to a noop function
* `wp_remove_targeted_link_rel_filters()`: converted to a noop function
The deprecated functions are retained in `formatting.php` as in `SHORTINIT` mode the file is included while `deprecated.php` is not.
This also removes the `noopener` from links hard coded within the WordPress dashboard linking to documentation and other resources.
Props audrasjb, azaozz, dhruval04, dorzki, neo2k23, presskopp, sabernhardt, swissspidy, tobiasbg.
Fixes#53843.
Built from https://develop.svn.wordpress.org/trunk@59120
git-svn-id: http://core.svn.wordpress.org/trunk@58516 1a063a9b-81f0-0310-95a4-ce76da25c4cd