update HiveExternalCatalogVersionsSuite to test 2.4.0

Author: cloud-fan

sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveExternalCatalogVersionsSuite.scala

@@ -206,7 +206,7 @@ class HiveExternalCatalogVersionsSuite extends SparkSubmitTestUtils {
 
 object PROCESS_TABLES extends QueryTest with SQLTestUtils {
   // Tests the latest version of every release line.
-  val testingVersions = Seq("2.1.3", "2.2.2", "2.3.2")
+  val testingVersions = Seq("2.1.3", "2.2.2", "2.3.2", "2.4.0")
 
   protected var spark: SparkSession = _