fix(composer): set minimum PHP version required to 7.4

Author: gaetan-hexadog

composer.json

@@ -14,6 +14,7 @@
     ],
     "minimum-stability": "stable",
     "require": {
+        "php": ">=7.4",
         "hexadog/laravel-theme-installer": "^1.0",
         "illuminate/view": "^7.0|^8.0|^9.0|^10.0"
     },