修改PHP版本为^7.4

composer.json

@@ -5,7 +5,7 @@
     "keywords": ["framework", "laravel"],
     "license": "MIT",
     "require": {
-        "php": "^7.3|^8.0",
+        "php": "^7.4|^8.0",
         "dcat/laravel-admin": "2.*",
         "fideloper/proxy": "^4.4",
         "fruitcake/laravel-cors": "^2.0",