Use pydantic.v1 namespace on all pydantic versions (#883)

With https://github.com/pydantic/pydantic/pull/9042 being shipped with
[1.10.15](https://docs.pydantic.dev/latest/changelog/#v11015-2024-04-03),
we can clean up the imports a bit until we make decisions how to move
onward with or without pydantic.

---------

Co-authored-by: Steven B. <51370195+sdb9696@users.noreply.github.com>

kasa/smart/modules/firmware.py

@@ -2,18 +2,15 @@
 
 from __future__ import annotations
 
+from datetime import date
 from typing import TYPE_CHECKING, Any, Optional
 
+from pydantic.v1 import BaseModel, Field, validator
+
 from ...exceptions import SmartErrorCode
 from ...feature import Feature
 from ..smartmodule import SmartModule
 
-try:
-    from pydantic.v1 import BaseModel, Field, validator
-except ImportError:
-    from pydantic import BaseModel, Field, validator
-from datetime import date
-
 if TYPE_CHECKING:
     from ..smartdevice import SmartDevice