IntrospectionQueryCache does not get hit as often as it should

We recently introduced caching on IntrospectionQueryCache !120279 (merged). However it seems that the cache is not always hit, even though the query should be cached, see https://log.gprd.gitlab.net/goto/72c41510-0536-11ee-a017-0d32180b1390. When we test it on production, we do hit the cache. We should investigate why this is.