Remove legacy PHP entry point, not needed nor wanted anymore

Timeless has required MW 1.29 or newer de facto for many months now, so
users should just use wfLoadSkin( 'Timeless' ); in their wiki's
LocalSettings.php to load the skin.

Change-Id: Ib34ffd24e9ce0b7d230ad5617366a0375bd594c7

Timeless.php

@@ -1,10 +0,0 @@
-<?php
-/**
- * This PHP entry point is deprecated. Please use wfLoadSkin() and the skin.json file
- * instead. See https://www.mediawiki.org/wiki/Manual:Extension_registration for more details.
- */
-if ( !function_exists( 'wfLoadSkin' ) ) {
-	die( 'The Timeless skin requires MediaWiki 1.25 or newer.' );
-}
-
-wfLoadSkin( 'Timeless' );