[SPARK-53673][CONNECT][TESTS] Fix a flaky test failure in SparkSessionE2ESuite - interrupt tag caused by the usage of ForkJoinPool

[sarutak]

What changes were proposed in this pull request?

This PR aims to fix one of the issues which block SPARK-48139.
In the problematic test interrupt tag in SparkSessionE2ESuite, four futures run on threads in ForkJoinPool and try to interrupt through tags.
A thread in a ForkJoinPool can create a spare thread and make it available in the pool so any of threads can be parent and child. It can happen when a thread performs a blocking operation. One example is ArrayBlockingQueue.take and it is called in a method provided by gRPC.

On the other hand, tags are inplemented as InheritableThreadLocal.
So, if the futures q1 and q4, or q2 and q3 are parent and child, tags should be inheritd, which causes the flaky test faulure.

You can easily reprodue the issue by inserting a sleep into the problematic test like as follows (don't forget to replace ignore with test).

   // TODO(SPARK-48139): Re-enable `SparkSessionE2ESuite.interrupt tag`
-  ignore("interrupt tag") {
+  test("interrupt tag") {
     val session = spark
     import session.implicits._
 
@@ -204,6 +204,7 @@ class SparkSessionE2ESuite extends ConnectFunSuite with RemoteSparkSession {
         spark.clearTags() // clear for the case of thread reuse by another Future
       }
     }(executionContext)
+    Thread.sleep(1000)
     val q4 = Future {
       assert(spark.getTags() == Set())
       spark.addTag("one")

And then, run the test.

$ build/sbt 'connect-client-jvm/testOnly org.apache.spark.sql.connect.SparkSessionE2ESuite -- -z "interrupt tag"'

Why are the changes needed?

For test stability.

Does this PR introduce any user-facing change?

No.

How was this patch tested?

Ran the problematic test with inserting sleep like mentioned above and it passed.

Was this patch authored or co-authored using generative AI tooling?

No.

[sarutak]

Intentionally keep the test as ignore because there is another cause of the flakiness.

[dongjoon-hyun]

It sounds reasonable to me as a partial improvement. Thank you, @sarutak .

[dongjoon-hyun]

Feel free to merge since the CI result is irrelevant to this PR because the test case is still ignored.

[sarutak]

Thank yoou @dongjoon-hyun @zhengruifeng @yaooqinn for the review!
Merged to master.

BTW, as far as I know, there is the last one issue which blocks SPARK-48139 and a PR tries to resolve it.
@zhengruifeng I'm happy if you are familiar with the area and can take a look at the PR.