Fix failing 131_sort_segments_migrate_to_data_stream test (#77845)

x-pack/plugin/src/yamlRestTest/resources/rest-api-spec/test/data_stream/131_sort_segments_migrate_to_data_stream.yml

@@ -22,6 +22,9 @@
       indices.create:
         index: test_index1
         body:
+          settings:
+            number_of_shards: 1
+            number_of_replicas: 0
           aliases:
             my_ds:
               is_write_index: true