removed a useless composer dependency

Author: Kharhamel

generator/composer.json

@@ -9,7 +9,6 @@
   "require": {
     "php": ">=7.1",
     "ext-simplexml": "*",
-    "phpoffice/phpspreadsheet": "^1.4",
     "ext-json": "^1.5",
     "symfony/console": "^4.1.4",
     "symfony/process": "^4.1",