[SPARK-51011][CORE] Add logging for whether a task is going to be interrupted when killed

### What changes were proposed in this pull request?

We now log the value of `interruptThread` when a `TaskRunner`'s `kill` method is killed. This should help with debugging when potential zombie Spark tasks do not seem to be exiting.

### Why are the changes needed?

Today, it's tricky to debug why a task is not exiting (and thus, why executors might be getting lost) without knowing for sure if it was issued a Java interrupt.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Ran `org.apache.spark.executor.ExecutorSuite` and verified the log looked as expected.

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

No.

Closes #49699 from neilramaswamy/spark-51011.

Lead-authored-by: Neil Ramaswamy <neil.ramaswamy@databricks.com>
Co-authored-by: Hyukjin Kwon <gurwls223@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>

Author: neilramaswamy

common/utils/src/main/scala/org/apache/spark/internal/LogKey.scala

@@ -331,6 +331,7 @@ private[spark] object LogKeys {
   case object INPUT extends LogKey
   case object INPUT_SPLIT extends LogKey
   case object INTEGRAL extends LogKey
+  case object INTERRUPT_THREAD extends LogKey
   case object INTERVAL extends LogKey
   case object INVALID_PARAMS extends LogKey
   case object ISOLATION_LEVEL extends LogKey

core/src/main/scala/org/apache/spark/executor/Executor.scala

@@ -504,8 +504,9 @@ private[spark] class Executor(
     @volatile var task: Task[Any] = _
 
     def kill(interruptThread: Boolean, reason: String): Unit = {
-      logInfo(log"Executor is trying to kill ${LogMDC(TASK_NAME, taskName)}," +
-        log" reason: ${LogMDC(REASON, reason)}")
+      logInfo(log"Executor is trying to kill ${LogMDC(TASK_NAME, taskName)}, " +
+        log"interruptThread: ${LogMDC(INTERRUPT_THREAD, interruptThread)}, " +
+        log"reason: ${LogMDC(REASON, reason)}")
       reasonIfKilled = Some(reason)
       if (task != null) {
         synchronized {