remove pydantic from customer_attributes.py

src/customer_attributes.py

@@ -1,22 +1,25 @@
+from dataclasses import dataclass, field
 from typing import ClassVar
-from pydantic import BaseModel, model_validator
+
 from src.models import KeypadSize
 from src.utils import generate_random_nonrepeating_list
 
 
-class CustomerAttributes(BaseModel):
+@dataclass
+class CustomerAttributes:
     attr_vals: list[int]
     set_vals: list[int]
     keypad_size: KeypadSize
     MAX_KEYS: ClassVar[int] = 256
     MAX_ATTRS_PER_KEY: ClassVar[int] = 256
 
-    @model_validator(mode='after')
-    def check_keys_vs_attrs(self) -> 'CustomerAttributes':
+    def __post_init__(self):
+        self.check_keys_vs_attrs()
+
+    def check_keys_vs_attrs(self) -> None:
         if self.keypad_size.is_dispersable:
             raise ValueError("number of keys must be less than the number of "
                              "attributes per key to be dispersion resistant")
-        return self
 
     @classmethod
     def create(cls, keypad_size: KeypadSize) -> 'CustomerAttributes':