fix(conversions): remove unused TypeVar from prefix_conversions_string

Author: iosayin

conversions/prefix_conversions_string.py

@@ -11,10 +11,6 @@
 from __future__ import annotations
 
 from enum import Enum, unique
-from typing import TypeVar
-
-# Create a generic variable that can be 'Enum', or any subclass.
-T = TypeVar("T", bound="Enum")
 
 
 @unique