CLI: Fix deduced option type for DynamicEntryPointCommandGroup

The `type` for the click command options were based of the `annotation`
property of the model fields. These annotations can sometimes be
compound, however, e.g, `Union[int, float]` and `Optional[str]` but
these are not supported by `click.option`. It would more or less work
for Python 3.10 and up, but it would except for Python 3.9 because the
type would be wrapped in the `click.FuncParamType` which would call
`__name__` on the type, but this was only added in Python 3.10.

The solution is to extract the arguments in case of a compound type. The
`typing.get_args()` method does just this. If the annotation is a plain
type, it simply returns an empty tuple.

aiida/cmdline/groups/dynamic.py

@@ -142,9 +142,15 @@ def list_options(self, entry_point: str) -> list:
 
             for key, field_info in cls.Configuration.model_fields.items():
                 default = field_info.default_factory if field_info.default is PydanticUndefined else field_info.default
+
+                # The ``field_info.annotation`` property returns the annotation of the field. This can be a plain type
+                # or a type from ``typing``, e.g., ``Union[int, float]`` or ``Optional[str]``. In these cases, the type
+                # that needs to be passed to ``click`` is the arguments of the type, which can be obtained using the
+                # ``typing.get_args()`` method. If it is not a compound type, this returns an empty tuplem so in that
+                # case, the type is simply the ``field_info.annotation``.
                 options_spec[key] = {
                     'required': field_info.is_required(),
-                    'type': field_info.annotation,
+                    'type': t.get_args(field_info.annotation) or field_info.annotation,
                     'prompt': field_info.title,
                     'default': default,
                     'help': field_info.description,

tests/cmdline/groups/test_dynamic.py

@@ -31,3 +31,4 @@ def test_list_options(entry_points):
         option = option_decorators(lambda x: True).__click_params__[0]
         field = CustomClass.Configuration.model_fields[option.name]
         assert option.default == field.default_factory if field.default is PydanticUndefined else field.default
+        assert option.type == t.get_args(field.annotation) or field.annotation