Add PHP 8.4 polyfill (#1260)

Closes #1259.

Author: theofidry

composer.json

@@ -24,6 +24,7 @@
         "fakerphp/faker": "^1.10",
         "myclabs/deep-copy": "^1.10",
         "sebastian/comparator": "^3.0 || ^4.0 || ^5.0 || ^6.0 || ^7.0",
+        "symfony/polyfill-php84": "^1.31",
         "symfony/property-access": "^6.4 || ^7.0",
         "symfony/yaml": "^6.0 || ^7.0"
     },