fix: updating type hints

Author: lachlangrose

LoopStructural/utils/_surface.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Optional, Union, Callable, List
+from typing import Optional, Union, Callable, List, Dict
 import numpy as np
 import numpy.typing as npt
 from LoopStructural.utils.logging import getLogger
@@ -15,7 +15,7 @@
 # from LoopStructural.interpolators._geological_interpolator import GeologicalInterpolator
 from LoopStructural.datatypes import Surface, BoundingBox
 
-surface_list = dict[str, Surface]
+surface_list = List[Surface]
 
 
 class LoopIsosurfacer: