Allow php-http/cache-plugin v2

Author: GrahamCampbell

composer.json

@@ -19,7 +19,7 @@
     "require": {
         "php": "^7.2.5 || ^8.0",
         "ext-json": "*",
-        "php-http/cache-plugin": "^1.7.1",
+        "php-http/cache-plugin": "^1.7.1|^2.0",
         "php-http/client-common": "^2.3",
         "php-http/discovery": "^1.12",
         "php-http/httplug": "^2.2",