[MINOR] improvement(test): Disable Spark UI for Spark integration tes…

…ts (#1831)

### What changes were proposed in this pull request?

Disable Spark UI for Spark integration tests.

### Why are the changes needed?

Spark UI is not necessary for test cases.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Existing UTs.

integration-test/spark-common/src/test/java/org/apache/uniffle/test/SparkIntegrationTestBase.java

@@ -105,7 +105,10 @@ protected Map runSparkApp(SparkConf sparkConf, String testFileName) throws Excep
   }
 
   protected SparkConf createSparkConf() {
-    return new SparkConf().setAppName(this.getClass().getSimpleName()).setMaster("local[4]");
+    return new SparkConf()
+        .setAppName(this.getClass().getSimpleName())
+        .setMaster("local[4]")
+        .set("spark.ui.enabled", "false");
   }
 
   public void updateSparkConfWithRssGrpc(SparkConf sparkConf) {