Keep SparkFunSuite-dependent methods in SQLTestUtils

Methods like withTempDir, testQuietly, testWithWholeStageCodegenOnAndOff
need SparkFunSuite and are used by suites that extend SQLTestUtils
(via SharedSparkSession) without extending QueryTest. Keep them in
SQLTestUtils; QueryTest class remains minimal.

Co-authored-by: Isaac

Author: zhengruifeng

sql/core/src/test/scala/org/apache/spark/sql/test/SQLTestUtils.scala

@@ -43,8 +43,12 @@ private[sql] trait SQLTestUtilsBase extends QueryTestBase { self: Suite => }
 /**
  * Helper trait that should be extended by all SQL test suites within the Spark
  * code base.
+ *
+ * This extends [[SparkFunSuite]] with [[QueryTestBase]] and adds test helpers that
+ * depend on [[SparkFunSuite]] (e.g. `test()` overrides, `withTempDir`).
  */
 private[sql] trait SQLTestUtils extends SparkFunSuite with SQLTestUtilsBase with PlanTest {
+
   /**
    * Creates a temporary directory, which is then passed to `f` and will be deleted after `f`
    * returns.