extra keywords in the reference object are permitted

see https://spec.openapis.org/oas/v3.1.0#fixed-fields-18

Author: karenetheridge

schemas/v3.1/schema.json

@@ -1054,8 +1054,7 @@
         "description": {
           "type": "string"
         }
-      },
-      "unevaluatedProperties": false
+      }
     },
     "schema": {
       "$comment": "https://spec.openapis.org/oas/v3.1.0#schema-object",

schemas/v3.1/schema.yaml

@@ -732,7 +732,6 @@ $defs:
         type: string
       description:
         type: string
-    unevaluatedProperties: false
 
   schema:
     $comment: https://spec.openapis.org/oas/v3.1.0#schema-object