remove sleep from unit test

tests/integration/test_asynchronous_metric_log_table/configs/asynchronous_metrics_update_period_s.xml

 <yandex>
-    <asynchronous_metrics_update_period_s>2</asynchronous_metrics_update_period_s>
+    <asynchronous_metrics_update_period_s>1</asynchronous_metrics_update_period_s>
 </yandex>

tests/queries/0_stateless/01473_event_time_microseconds.sql

@@ -7,7 +7,6 @@ set log_queries = 1;
 
 select '01473_metric_log_table_event_start_time_microseconds_test';
 system flush logs;
-SELECT sleep(3) Format Null;
 -- query assumes that the event_time field is accurate.
 WITH (
     (