fix(core.grids.py): fixes error related to python 3.8 not supporting …

…new type annotation Dict-dict List-list

src/eyepy/core/grids.py

@@ -4,15 +4,16 @@
 from collections.abc import Sequence
 import functools
 import logging
-from typing import Any, Iterable, Optional, Union
+from typing import Any, Iterable, Optional, TYPE_CHECKING, Union
 
 import numpy as np
 import numpy.typing as npt
 from skimage import transform
 
 logger = logging.getLogger(__name__)
 
-Shape = Union[int, tuple[int, int]]
+if TYPE_CHECKING:
+    Shape = Union[int, tuple[int, int]]
 
 
 def circle_mask(radius: int,