Remove unused TypeVar from bubble sort (#15491)

The PEP 695 type parameters already bound T to Comparable, so the module-level TypeVar was unused. Matches the cleanup requested in #15234.

Author: HarshRajSinghania

sorts/bubble_sort.py

@@ -1,13 +1,10 @@
-from typing import Any, Protocol, TypeVar
+from typing import Any, Protocol
 
 
 class Comparable(Protocol):
     def __lt__(self, other: Any, /) -> bool: ...
 
 
-T = TypeVar("T", bound=Comparable)
-
-
 def bubble_sort_iterative[T: Comparable](collection: list[T]) -> list[T]:
     """Pure implementation of the bubble sort algorithm in Python (iterative).