Fix php is required both in require and require-dev, this can lead to unexpected behavior

Author: widoz

composer.json

@@ -35,7 +35,6 @@
     "wimg/php-compatibility": "^8.0"
   },
   "require-dev": {
-    "php": ">=7.0",
     "phpunit/phpunit": "6.0.*"
   },
   "autoload-dev": {