[TASK] migrate to Icons.php

Configuration/Icons.php

+<?php
+
+/**
+ * Important! Do not return a variable named $icons, because it will result in an error.
+ * The core requires this file and then the variable names will clash.
+ * Either use a closure here, or do not call your variable $icons.
+ */
+
+$iconList = [];
+foreach (['extension-sg_youtube' => 'youtube.svg'] as $identifier => $path) {
+	$iconList[$identifier] = [
+		'provider' => \TYPO3\CMS\Core\Imaging\IconProvider\SvgIconProvider::class,
+		'source' => 'EXT:sg_youtube/Resources/Public/Icons/' . $path,
+	];
+}
+
+return $iconList;

ext_localconf.php

@@ -13,14 +13,6 @@
 	'@import "EXT:sg_youtube/Configuration/TsConfig/Page/NewContentElementWizard.tsconfig"'
 );
 
-// Register Icons
-$iconRegistry = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Core\Imaging\IconRegistry::class);
-$iconRegistry->registerIcon(
-	'extension-sg_youtube',
-	\TYPO3\CMS\Core\Imaging\IconProvider\SvgIconProvider::class,
-	['source' => 'EXT:sg_youtube/Resources/Public/Icons/youtube.svg']
-);
-
 // Caching
 $GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['sgyoutube_cache'] ??= [];