Remove temporary test_output.txt file

This file was created during testing and is causing spelling check errors in the pipeline.

Author: Changjian Wang

sdk/contentunderstanding/azure-ai-contentunderstanding/src/test/java/com/azure/ai/contentunderstanding/generated/ContentUnderstandingClientTestBase.java

@@ -27,7 +27,7 @@ class ContentUnderstandingClientTestBase extends TestProxyTestBase {
      * Utility method to check if required environment variables are available.
      * If they are not available, the test will be skipped.
      * This is useful for integration tests that require real Azure credentials.
-     * 
+     *
      * Both CONTENTUNDERSTANDING_ENDPOINT and AZURE_CONTENT_UNDERSTANDING_KEY must be set
      * for the test to run. If either is missing, the test is skipped.
      */