[TEST] Removes timeout based wait_for_active_shards REST test (#23360)

This commit removes an necessary test that ensures if
wait_for_active_shards cannot be fulfilled on index creation, that the
response returns shardsAcknowledged=false.  However, this is already
tested in WaitForActiveShardsIT and it would improve the speed of the
test runs to get rid of any unnecessary tests, especially those that
depend on timeouts.

rest-api-spec/src/main/resources/rest-api-spec/test/indices.create/10_basic.yaml

@@ -30,25 +30,6 @@
 
   - match: { test_index.settings.index.number_of_replicas: "0"}
 
----
-"Create index with too large wait_for_active_shards":
-
-  - do:
-      indices.create:
-        index: test_index
-        timeout: 300ms
-        master_timeout: 300ms
-        wait_for_active_shards: 6
-        body:
-          settings:
-            number_of_replicas: 5
-
-  - match: { shards_acknowledged: false }
-
-  - do:
-      cluster.health:
-          wait_for_events: urgent      
-
 ---
 "Create index with wait_for_active_shards set to all":