PyObjecty.cleanup_on_thread=true breaks java-to-python tests for jpy-integration

[niloc132]

Steps to reproduce:

• in py/jpy-integration/src/javaToPython/build.gradle.template remove the PyObject.cleanup_on_thread, or switch it to try
• try to run :jpy-integration:testJavaToPython

Expected, test passes with the flag set or not.

Actual:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007ffb1e0ae863, pid=174, tid=0x00007ffa47434700
#
# JRE version: OpenJDK Runtime Environment (Zulu 8.54.0.21-CA-linux64) (8.0_292-b10) (build 1.8.0_292-b10)
# Java VM: OpenJDK 64-Bit Server VM (25.292-b10 mixed mode linux-amd64 compressed oops)
# Problematic frame:
# V  [libjvm.so+0x688863]  JavaCallArguments::parameters()+0xa3
#
# Core dump written. Default location: /project/core or core.174
#
# An error report file with more information is saved as:
# /project/hs_err_pid174.log
#
# If you would like to submit a bug report, please visit:
#   http://www.azulsystems.com/support/
#

io.deephaven.jpy.JpyModuleByteArrayTest > pyObjectFromArrayLen SKIPPED

For now this works with just setting that flag when running tests.

The task :jpy-integration:unittest-python-to-java, and related also use py/jpy-integration/src/pythonToJava/jpyconfig.py.template, which also has this flag set - instead of failing, the test seems to hang (tested for over an hour, never finished or progressed).