ifcopenshell.validate - remove simple_spf dependency (689289b)

Moved it to `TYPE_CHECKING` since it's currently used just for typing.

Was breaking validation in Bonsai since it doesn't provide all submodules with IfcOpenShell https://github.com/IfcOpenShell/IfcOpenShell/issues/6723#issuecomment-3016223786

Also added a simple test so github workflow would catch a simple error like this.

src/bonsai/test/bim/feature/debug.feature

@@ -26,3 +26,9 @@ Scenario: Use the inspector - inspect from object
     When the object "IfcProject/My Project" is selected
     And I press "bim.inspect_from_object"
     Then nothing happens
+
+Scenario: Run IFC validation
+    Given an empty IFC project
+    And I load the demo construction library
+    And I press "bim.validate_ifc_file"
+    Then nothing happens

src/ifcopenshell-python/ifcopenshell/validate.py

@@ -42,6 +42,7 @@ options:
 
 """
 
+from __future__ import annotations
 import os
 import sys
 import json
@@ -50,7 +51,7 @@ import types
 import argparse
 
 from collections import namedtuple
-from typing import Union, Any, Optional
+from typing import Union, Any, Optional, TYPE_CHECKING
 from collections.abc import Iterator
 from logging import Logger, Handler
 
@@ -60,11 +61,13 @@ else:
     EllipsisType = type(...)
 
 import ifcopenshell
-import ifcopenshell.simple_spf
 import ifcopenshell.ifcopenshell_wrapper
 import ifcopenshell.ifcopenshell_wrapper as W
 import ifcopenshell.express.rule_executor
 
+if TYPE_CHECKING:
+    import ifcopenshell.simple_spf
+
 named_type = ifcopenshell.ifcopenshell_wrapper.named_type
 aggregation_type = ifcopenshell.ifcopenshell_wrapper.aggregation_type
 simple_type = ifcopenshell.ifcopenshell_wrapper.simple_type