feat(ci): setup GitHub Action runners for building Python from source #226
Description
Problem
While Python's current version coverage is good (3.12+ fully covered), historical versions (3.5–3.11 early patches) have platform gaps because astral-sh/python-build-standalone didn't exist when those versions were current. For completeness and future-proofing, we should be able to build Python from source when prebuilt binaries aren't available.
Proposed Solution
Create a GitHub Actions workflow that can build Python from source for missing platform/version combinations and upload the resulting binaries to R2.
Scope
- Build Python from source on macOS (arm64, amd64) and Linux (arm64, amd64) runners
- Upload built binaries to R2 with proper metadata
- Trigger when gaps are detected in manifests after mirror sync
- Only build versions that are missing from specific platforms
- Lower priority than Node.js and Ruby since current Python versions are well-covered