Add pip wheel cache parser for origin.json files

[Jayant-kernel]

Implements PipCacheWheelHandler to parse origin.json files created by pip when caching built wheels. Extracts package metadata including name, version, download URL, and SHA256 hash.

Fixes #4220

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Summary

Adds support for parsing pip wheel cache origin.json files to detect cached Python packages.

Implementation

• Added PipCacheWheelHandler in src/packagedcode/pypi.py
• Parses origin.json files from ~/.cache/pip/wheels/ directories
• Extracts package name, version, download URL, and SHA256 hash
• Registered handler in APPLICATION_PACKAGE_DATAFILE_HANDLERS

Testing

• Added test case test_parse_pip_cache_wheel in tests/packagedcode/test_pypi.py
• Includes real construct package origin.json as test fixture
• Validates correct extraction of all package metadata

Example

Input: ~/.cache/pip/wheels/.../origin.json

{
  "archive_info": {"hash": "sha256=7b2a3fd8e5f597a5aa1d614c3bd516fa065db01704c72a1efaaeec6ef23d8b45"},
  "url": "https://files.pythonhosted.org/packages/.../construct-2.10.68.tar.gz"
}

Output:

• Name: construct
• Version: 2.10.68
• PURL: pkg:pypi/construct@2.10.68
• SHA256 hash extracted and cleaned

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Tasks

• Reviewed contribution guidelines
• PR is descriptively titled 📑 and links the original issue above 🔗
• Tests pass -- look for a green checkbox ✔️ a few minutes after opening your PR
• Commits are in uniquely-named feature branch and has no merge conflicts 📁
• Updated documentation pages (not applicable - internal handler)
• Updated CHANGELOG.rst (not applicable - maintainers handle this)

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## **CHECKLIST EXPLANATION:**

- [x] Reviewed contribution guidelines
- [x] PR is descriptively titled  
- [x] Tests pass (you ran them locally)
- [x] Commits in feature branch (fix-4220-pip-cache-parser)

Signed-off-by: Jayant [jayantmcom@gmail.com](mailto:jayantmcom@gmail.com)