Fix warning typo for test failure (#106971) (#106976)

This had the wrong index patterns, which led to test failures

Resolves #106965

modules/data-streams/src/yamlRestTest/resources/rest-api-spec/test/data_stream/10_basic.yml

@@ -543,7 +543,7 @@ setup:
 
   - do:
       allowed_warnings:
-        - "index template [my-template4] has index patterns [failure-data-stream1, failure-data-stream2] matching patterns from existing older templates [global] with patterns (global => [*]); this template [my-template4] will take precedence during new index creation"
+        - "index template [my-template4] has index patterns [failure-data-stream1] matching patterns from existing older templates [global] with patterns (global => [*]); this template [my-template4] will take precedence during new index creation"
       indices.put_index_template:
         name: my-template4
         body: