Migrate callbacks to hooks

[marcusboon]

On Moodle 4.5 we are seeing this show up when debugging is turned up

Callback after_config in mod_cms component should be migrated to new hook callback for core\hook\after_config

    line 7228 of /lib/moodlelib.php: call to debugging()
    line 7342 of /lib/moodlelib.php: call to {closure}()
    line 36 of /lib/classes/hook/after_config.php: call to get_plugins_with_function()
    line 1200 of /lib/setup.php: call to core\hook\after_config->process_legacy_callbacks()
    line 260 of /config.php: call to require_once()
    line 87 of /admin/index.php: call to require()