Redact auth in wheel cache origin warnings

[carrerasdarren-cell]

What does this PR do?

Fixes #14232.

record_download_origin() writes a credential-stripped PEP 610 URL to origin.json, but previously compared and logged the raw in-memory URL. Re-recording an authenticated origin therefore produced a false mismatch warning containing the username and password.

This change compares the same serialized URL representation that is written to disk and uses those stripped values in genuine mismatch warnings. It adds regression coverage for both behaviors.

PR Checklist:

• I agree to follow the PSF Code of Conduct.
• I have read and have followed the CONTRIBUTING.md file.
• I have added a news file fragment.
• I have read and followed the AI_POLICY.md file, and I take full ownership and responsibility for every line.

Assisted-by: OpenAI Codex

Tests

• pytest -q tests/unit/test_cache.py: 10 passed
• Black 26.5.1 passed
• Ruff 0.15.20 passed
• Mypy 2.1.0 passed for both changed Python files
• git diff --check passed