Unmuting UpgradeClusterClientYamlTestSuiteIT for risk assesment (#100579)

Author: cbuescher

x-pack/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/10_basic.yml

@@ -1,8 +1,5 @@
 ---
 "Continue scroll after upgrade":
-  - skip:
-      version: "all"
-      reason: "AwaitsFix https://github.com/elastic/elasticsearch/issues/91637"
   - do:
       get:
         index: scroll_index