Avoid shutdown recursion

[liamhuber]

In executorlib-1.8.2, which cancels futures when the executor is .shutdown.

This gets us into a recursive pickle when the _finish_run callback internall shuts down the executor. Passing that shutdown over to a separate, patient thread resolves all the issues in the local tests for executorlib-1.8.2. I need the CI to see if it also resolves the issue running with SLURM

[github-actions]

👈 Launch a binder notebook on branch pyiron/pyiron_workflow/shutdown-recursion

[jan-janssen]

@liamhuber This should also work fine for 1.9.0 - as tested in #812

[liamhuber]

@liamhuber This should also work fine for 1.9.0

That's my hope. I just checked it out locally and am re-running the tests (sans SLURM), but it is not yet going nicely...

[liamhuber]

Yeah, locally I'm getting ResourceWarning: Enable tracemalloc to get the object allocation traceback and the cache test just hangs. Aha, and same thing on CI https://github.com/pyiron/pyiron_workflow/actions/runs/22594515927/job/65460954301?pr=817#step:4:1909

[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 93.36%. Comparing base (7035b23) to head (05bd76f).
⚠️ Report is 8 commits behind head on main.

Files with missing lines	Patch %	Lines
pyiron_workflow/mixin/run.py	50.00%	1 Missing ⚠️

❌ Your patch status has failed because the patch coverage (50.00%) is below the target coverage (95.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #816      +/-   ##
==========================================
- Coverage   93.46%   93.36%   -0.11%     
==========================================
  Files          38       38              
  Lines        3873     3873              
==========================================
- Hits         3620     3616       -4     
- Misses        253      257       +4     

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