Use constant MW_VERSION instead of deprecated global $wgVersion

Change-Id: I612dcdd63f4908cc2b3a6123191a16f4bd7c4452

includes/SkinTimeless.php

@@ -12,11 +12,10 @@ class SkinTimeless extends SkinTemplate {
 	public function __construct(
 		array $options = []
 	) {
-		global $wgVersion;
 		$out = $this->getOutput();
 
 		// This code block can be removed when 1.35 is no longer supported.
-		if ( version_compare( $wgVersion, '1.36', '<' ) ) {
+		if ( version_compare( MW_VERSION, '1.36', '<' ) ) {
 			// Add external links - this is replaced by `content-links` feature in 1.36
 			$out->addModuleStyles( [
 				'mediawiki.skinning.content.externallinks'

includes/TimelessVariablesModule.php

@@ -12,8 +12,7 @@ class TimelessVariablesModule extends ResourceLoaderSkinModule {
 			$localBasePath = null,
 			$remoteBasePath = null
 	) {
-			global $wgVersion;
-			if ( version_compare( $wgVersion, '1.36', '<' ) ) {
+			if ( version_compare( MW_VERSION, '1.36', '<' ) ) {
 				$options['features'] = [ "logo", "legacy" ];
 			}