Remove unused TypeVar from bubble sort

[HarshRajSinghania]

Describe your change

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both the logic and the tests in a single pull request.
• Documentation change?

Checklist

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized it.
• All filenames are in PascalCase or snake_case (no spaces or hyphens).
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
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• If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: Fixes #ISSUE-NUMBER.

Summary
sorts/bubble_sort.py still imported TypeVar and assigned T = TypeVar("T", bound=Comparable) even though both functions already use PEP 695 parameters (def bubble_sort_iterative[T: Comparable] and def bubble_sort_recursive[T: Comparable]). That module-level TypeVar is unused.

Motivation
Follow-up requested on #15234: drop the leftover TypeVar step now that the comparison sorts use a bounded type parameter. This PR only covers bubble_sort.py.

Implementation
Removed the TypeVar import and the unused T = TypeVar(...) assignment. The Comparable protocol and the existing function signatures are unchanged.

Testing
uv run --python 3.12 python -m doctest -v sorts/bubble_sort.py
42 tests passed, 0 failed.
uv run --python 3.12 python -m py_compile sorts/bubble_sort.py succeeded.

Refs #15234

[cclauss]

uv run --python 3.12

This repo only supports Python >= 3.15t