Increase scroll timeout for upgrade test (#51912)

Bumps the timeout already bumped in #50195, which was insufficient.

Author: ywelsch

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

@@ -34,7 +34,7 @@
         rest_total_hits_as_int: true
         index: upgraded_scroll
         size: 1
-        scroll: 10m
+        scroll: 60m
         sort: foo
         body:
           query: