update upload-test.sh and remove default allowed DAG (GoogleCloudPlatform#825)

Author: severus-ho

plugins/allow_list.txt

@@ -1,6 +1 @@
 on_failure_actions_trigger
-maxtext_sft_trainer
-maxtext_configs_aot
-maxtext_convergence
-maxtext_end_to_end
-maxtext_profiling

scripts/upload-tests.sh

@@ -31,7 +31,6 @@ if [[ "$GCS_DAGS_FOLDER" == */dags ]]; then
     ROOT_PATH="${GCS_DAGS_FOLDER%/dags}"
 fi
 
-gsutil -m rsync -r -d -x '.*\.md$' plugins "$ROOT_PATH"/plugins
-
+gsutil -m rsync -c -d -r -x '.*\.(md|txt)$' plugins "$ROOT_PATH"/plugins
 
 echo "Successfully uploaded tests."