Collaboration: Add missing maxItems to REST schema fixture

The rooms array schema includes a maxItems constraint of 50, but
the committed wp-api-generated.js fixture was missing it, causing
git diff --exit-code to fail on every PHPUnit CI job.

Author: josephfusco

tests/qunit/fixtures/wp-api-generated.js

@@ -12875,6 +12875,7 @@ mockedApiResponse.Schema = {
                                 "type": "object"
                             },
                             "type": "array",
+                            "maxItems": 50,
                             "required": true
                         }
                     }
@@ -12988,6 +12989,7 @@ mockedApiResponse.Schema = {
                                 "type": "object"
                             },
                             "type": "array",
+                            "maxItems": 50,
                             "required": true
                         }
                     }