Fix: add login icon as a server render dependency of main menu

The profile icon is necessary for logged in users. This is known when
parsing skin.json but was not added in MinervaHooks.php. This patch adds
the dependency unconditionally although it is only needed for the server
render of Special:MobileMenu for logged in users.

Bug: T196893
Change-Id: I2a8485299162c01d28ca1b07e7071ad0c0ef44fc

includes/MinervaHooks.php

@@ -118,6 +118,7 @@ class MinervaHooks {
 			switch ( $name ) {
 				case 'MobileMenu':
 					$out->addModuleStyles( [
+						'skins.minerva.icons.images.variants',
 						'skins.minerva.mainMenu.icons',
 						'skins.minerva.mainMenu.styles',
 					] );