fix: fix prometheus reporter test

Author: fishtailfu

polaris-plugins/polaris-plugins-observability/stat-prometheus/src/test/java/com/tencent/polaris/plugins/stat/prometheus/plugin/PrometheusReporterTest.java

@@ -108,13 +108,13 @@ public void testExpiredDataClean() throws InterruptedException {
 
         // mock push
         LOG.info("first mock push finish...");
-        Thread.sleep(pushInterval + 1000);
+        Thread.sleep(pushInterval + 50);
         Double result = getServiceCallTotalResult(callResult);
         Assert.assertEquals(new Double(count), result);
 
         // mock next push
         LOG.info("second mock push finish...");
-        Thread.sleep(pushInterval + 1000);
+        Thread.sleep(pushInterval + 50);
         result = getServiceCallTotalResult(callResult);
         Assert.assertEquals(new Double(0), result);