Update required PHP version to 8.0

Author: jr-cologne

composer.json

@@ -2,7 +2,7 @@
     "name": "colognifornia/colognifornia.com",
     "description": "The source code of colognifornia.com.",
     "require": {
-        "php": ">=7.4",
+        "php": ">=8.0",
         "slim/slim": "^4.2",
         "slim/psr7": "^1.6.0",
         "php-di/slim-bridge": "^3.0",