Fix example logs repeating themselves (#16669)

Move declaration of log streams to before tests, so that results won't get compounded on top of each other

examples/research_projects/rag/_test_finetune_rag.py

@@ -18,6 +18,9 @@ from transformers.testing_utils import (
 logging.basicConfig(level=logging.DEBUG)
 logger = logging.getLogger()
 
+stream_handler = logging.StreamHandler(sys.stdout)
+logger.addHandler(stream_handler)
+
 
 class RagFinetuneExampleTests(TestCasePlus):
     def _create_dummy_data(self, data_dir):
@@ -31,9 +34,6 @@ class RagFinetuneExampleTests(TestCasePlus):
                     f.write(content)
 
     def _run_finetune(self, gpus: int, distributed_retriever: str = "pytorch"):
-        stream_handler = logging.StreamHandler(sys.stdout)
-        logger.addHandler(stream_handler)
-
         tmp_dir = self.get_auto_remove_tmp_dir()
         output_dir = os.path.join(tmp_dir, "output")
         data_dir = os.path.join(tmp_dir, "data")