[skip ci] Drop legacy library

Author: contactashish13

composer.json

@@ -22,7 +22,6 @@
   },
   "require": {
     "codeinwp/themeisle-sdk": "master",
-    "xrstf/composer-php52": "^1.0.20",
     "phpoffice/phpspreadsheet": "1.8.2",
     "neitanod/forceutf8": "~2.0"
   },
@@ -33,16 +32,5 @@
     ]
   },
   "minimum-stability": "dev",
-  "prefer-stable": true,
-  "scripts": {
-    "post-install-cmd": [
-      "xrstf\\Composer52\\Generator::onPostInstallCmd"
-    ],
-    "post-update-cmd": [
-      "xrstf\\Composer52\\Generator::onPostInstallCmd"
-    ],
-    "post-autoload-dump": [
-      "xrstf\\Composer52\\Generator::onPostInstallCmd"
-    ]
-  }
-}
+  "prefer-stable": true
+}