ci: add graalpy

[henryiii]

Hitting an issue in scikit-hep/boost-histogram#1016:

 <         File "/tmp/pip-build-env-n4l8ms0l/overlay/lib/python3.11/site-
    packages/scikit_build_core/build/metadata.py", line 44, in
    get_standard_metadata
  <           new_pyproject_dict["project"] = process_dynamic_metadata(
  <         File "/tmp/pip-build-env-n4l8ms0l/overlay/lib/python3.11/site-
    packages/scikit_build_core/builder/_load_provider.py", line 149, in
    process_dynamic_metadata
  <           return dict(settings)
  <         File "/opt/_internal/graalpy311-
    graalpy242_311_native/lib/python3.11/_collections_abc.py", line 837, in
    __iter__
  <           yield from self._mapping
  <         File "/tmp/pip-build-env-n4l8ms0l/overlay/lib/python3.11/site-
    packages/scikit_build_core/builder/_load_provider.py", line 128, in __iter__
  <           yield from self.providers
  <       RuntimeError: dictionary changed size during iteration

Let's see if we can reproduce in tests.