chore: add scheduler tasks switch in docker .env

docker/.env.example

@@ -1168,3 +1168,13 @@ QUEUE_MONITOR_THRESHOLD=200
 QUEUE_MONITOR_ALERT_EMAILS=
 # Monitor interval in minutes, default is 30 minutes
 QUEUE_MONITOR_INTERVAL=30
+
+# Celery schedule tasks configuration
+ENABLE_CLEAN_EMBEDDING_CACHE_TASK=false
+ENABLE_CLEAN_UNUSED_DATASETS_TASK=false
+ENABLE_CREATE_TIDB_SERVERLESS_TASK=false
+ENABLE_UPDATE_TIDB_SERVERLESS_STATUS_TASK=false
+ENABLE_CLEAN_MESSAGES=false
+ENABLE_MAIL_CLEAN_DOCUMENT_NOTIFY_TASK=false
+ENABLE_DATASETS_QUEUE_MONITOR=false
+ENABLE_CHECK_UPGRADABLE_PLUGIN_TASK=true