fix: Correct indentation in assertion message for thread dump tests

- Adjusted the indentation of the expected truncation message assertion in ThreadDumpUtilsSuite for improved readability and consistency in test output.

Author: wangzhigang1999

kyuubi-common/src/test/scala/org/apache/kyuubi/util/ThreadDumpUtilsSuite.scala

@@ -118,7 +118,7 @@ class ThreadDumpUtilsSuite extends KyuubiFunSuite {
       assert(
         limitedSection.get.contains(s"... (${expectedMoreFrames} more stack frames)"),
         s"Dump did not contain the expected truncation message. " +
-        s"Expected '... ($expectedMoreFrames more stack frames)'.")
+          s"Expected '... ($expectedMoreFrames more stack frames)'.")
 
     } finally {
       if (deepStackThread != null) deepStackThread.interrupt()