VirtualThread stress test PingPong times out

java/lang/Thread/virtual/stress/PingPong.java (SQ and LTQ) tests by default perform 500,000 iterations,
see: https://github.com/openjdk/jdk21u/blob/eced83e13090748218ab3dac78f6ff1bddf2b158/test/jdk/java/lang/Thread/virtual/stress/PingPong.java#L28
this typically far exceeds the default 15 minutes openjdk jtreg timeout

On a typical Windows machine it achieves around 30,000 in 15 minutes before timing out.

These two tests need an additional "iterations" parameter with a lower value to run within the 15 minutes.
Note, this has been seen failing on other platforms too, eg:aarch64_linux.

ref:https://github.com/adoptium/ci-jenkins-pipelines/issues/1104#issuecomment-2399379492

Start with java/lang/Thread/virtual/stress/PingPong.java, especially the default iteration setting around line 28 and the SQ and LTQ tests. Run the tests with the default jtreg timeout and compare their progress on a typical Windows machine or aarch64_linux. Done means both tests use an iterations value that completes within the default 15-minute timeout.

Written by the indexing model from the issue text.