Fix mypy and ruff errors

virtualizarr/codecs.py

@@ -87,7 +87,10 @@ def _get_zarr_array_codecs(
         raise NotImplementedError(
             f"zarr-python v3 or higher is required, but version {installed_version} is installed."
         )
-    from zarr.core.metadata import ArrayV2Metadata, ArrayV3Metadata
+    from zarr.core.metadata import (  # type: ignore[import-untyped]
+        ArrayV2Metadata,
+        ArrayV3Metadata,
+    )
 
     # For zarr format v3
     if isinstance(array.metadata, ArrayV3Metadata):

virtualizarr/writers/icechunk.py

@@ -1,4 +1,4 @@
-from typing import TYPE_CHECKING, Optional, cast
+from typing import TYPE_CHECKING, List, Optional, Union, cast
 
 import numpy as np
 from xarray import Dataset
@@ -150,7 +150,7 @@ def get_axis(
 def check_compatible_arrays(
     ma: "ManifestArray", existing_array: "Array", append_axis: int
 ):
-    arrays = [ma, existing_array]  # type: List[Union[ManifestArray, Array]]
+    arrays: List[Union[ManifestArray, Array]] = [ma, existing_array]
     check_same_dtypes([arr.dtype for arr in arrays])
     check_same_codecs([get_codecs(arr, normalize_to_zarr_v3=True) for arr in arrays])
     check_same_chunk_shapes([arr.chunks for arr in arrays])