Keep only modules as requirements.

Author: LOBsTerr

composer.json

@@ -17,7 +17,6 @@
   "license": "GPL-2.0-or-later",
   "minimum-stability": "dev",
   "require": {
-    "drupal/core": "^8.8 || ^9",
     "drupal/migrate_plus": "^5.1",
     "drupal/migrate_tools": "^5.0",
     "drupal/geofield": "^1.16"