fix(client): remove duplicate outputAsJson function

Author: dtmeadows

openai-java-core/src/main/kotlin/com/openai/models/responses/ResponseInputItem.kt

@@ -2735,14 +2735,6 @@ private constructor(
             /** Text, image, or file output of the function tool call. */
             fun output(output: Output) = output(JsonField.of(output))
 
-            /**
-             * Sets the output to text representing the JSON serialized form of a given object. This
-             * is useful when passing data that is the result of a function call.
-             *
-             * @see output
-             */
-            fun outputAsJson(functionResult: Any) = apply { output(toJsonString(functionResult)) }
-
             /**
              * Sets [Builder.output] to an arbitrary JSON value.
              *