Ensure base type validation can handle non-dictionary values

The update introduces a condition to verify whether the values being validated are a dictionary before attempting to handle UNSET_TYPE in the aiogram base type. This adjustment helps to prevent potential errors or incorrect validation when non-dictionary values are faced.

aiogram/types/base.py

@@ -28,6 +28,8 @@ class TelegramObject(BotContextController, BaseModel):
         but UNSET might be passed to a model initialization from `Bot.method_name`,
         so we must take care of it and remove it before fields validation.
         """
+        if not isinstance(values, dict):
+            return values
         return {k: v for k, v in values.items() if not isinstance(v, UNSET_TYPE)}