C++ test failure

[JohanMabille]

The C++ tests fail almost immediatly with the following output:

If you want to connect to this kernel from an other client, you can use the kernel-debug.json file.
Run with XEUS 3.0.5
XDEBUGGER: the debugger has started
Fatal Python error: PyThreadState_Get: the function must be called with the GIL held, but the GIL is released (the current Python thread state is NULL)
Python runtime state: initialized

Thread 0x00007fbc26ffe700 (most recent call first):
  File "/home/runner/micromamba-root/envs/xeus-python/lib/python3.11/threading.py", line 324 in wait
  File "/home/runner/micromamba-root/envs/xeus-python/lib/python3.11/threading.py", line 6[22](https://github.com/jupyter-xeus/xeus-python/actions/runs/4820142844/jobs/8584231592#step:11:23) in wait
  File "/home/runner/micromamba-root/envs/xeus-python/lib/python3.11/site-packages/debugpy/_vendored/pydevd/pydevd.py", line 261 in _on_run
  File "/home/runner/micromamba-root/envs/xeus-python/lib/python3.11/site-packages/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_daemon_thread.py", line 49 in run
  File "/home/runner/micromamba-root/envs/xeus-python/lib/python3.11/threading.py", line 1038 in _bootstrap_inner
  File "/home/runner/micromamba-root/envs/xeus-python/lib/python3.11/threading.py", line 995 in _bootstrap

The only difference spotted with the last commit where they pass is the version of debugpy: 1.6.7 (failing) vs 1.6.6 (passing).

Tests have been disabled until we figure that out.