chore: remove unused six dependency

[sumanjeet0012]

Fixes #45

Description

This pull request removes the six dependency from pyproject.toml.

six was originally included as a Python 2/3 compatibility library. However, since this project enforces a minimum Python version of 3.10 (requires-python = ">=3.10, <4.0"), six is completely unnecessary. Furthermore, an inspection of the codebase confirms that six is not imported or used anywhere within the project's source, tests, or documentation.

Changes Made

• Removed "six>=1.10.0,<2.0" from the dependencies list in pyproject.toml.

Verification

• Confirmed absence of six usage via grep across multibase/, tests/, and docs/.
• Verified that all 266 tests pass successfully (pytest tests/).
• Verified that all linter and formatting checks pass (make lint).

[acul71]

Review summary (PR #49)

Thanks for the clean dependency cleanup — removing unused six from pyproject.toml correctly addresses #45 given requires-python >= 3.10 and no imports of six in the codebase.

Critical blocker — missing newsfragment

• Severity: CRITICAL / BLOCKER

• Issue: No newsfragments/45.<type>.rst file is present.

• Required: Add a newsfragment using issue 45, e.g. newsfragments/45.removal.rst (or 45.misc.rst / 45.internal.rst), with a short user-facing ReST line ending in a newline. Example:

  Removed unused ``six`` dependency (Python 2/3 compatibility shim no longer needed for Python ≥3.10).
  

PR approval is blocked until this file is added.

Other findings

• Branch sync: Diverged — 6 behind / 1 ahead of origin/master. Dry-run merge: no conflicts. Optional update recommended for currency.
• Overlap (informational): pyproject.toml also touched by open PRs #56 and #57; watch merge ordering later.
• Security: None.
• Local checks (after venv restore): make lint, make typecheck, make test (266 passed), make docs-ci — all exit 0.
• CI: All GitHub checks pass.

Overall assessment

• Quality: Good
• Merge readiness: Needs fixes (newsfragment) — requesting changes
• Confidence: High

Full report: maintainer artifact downloads/AI-PR-REVIEWS/49/AI-PR-REVIEW-49-0.md (local).