[HOTFIX][TESTS] HiveExternalCatalogVersionsSuite should ignore preview release

Author: dongjoon-hyun

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

@@ -237,6 +237,7 @@ object PROCESS_TABLES extends QueryTest with SQLTestUtils {
       Source.fromURL(s"${releaseMirror}/spark").mkString
         .split("\n")
         .filter(_.contains("""<li><a href="spark-"""))
+        .filterNot(_.contains("preview"))
         .map("""<a href="spark-(\d.\d.\d)/">""".r.findFirstMatchIn(_).get.group(1))
         .filter(_ < org.apache.spark.SPARK_VERSION)
     } catch {