[tejasng053]

What's changed?

package.info() currently leaves repository_download_url unset for PyPI packages, even when the release includes a source distribution. For a release containing a wheel followed by an sdist, callers receive the wheel's download_url but no link to its source archive.

Select the release file whose packagetype is sdist and expose its URL as repository_download_url. Preserve the existing first-file download_url behavior and leave the source URL unset when no sdist is available. Selection stays specific to each release, including requests for a single version.

Add ten mocked regression cases covering file ordering, source-only and wheel-only releases, missing metadata, empty releases, per-release URLs, and version filtering. Update the existing Flask fixture and changelog.

Related issue

Fixes #134

Validation

• New regressions before the fix: 5 failed and 5 passed; failures showed the missing source URL.
• All PyPI package metadata tests after the fix: 11 passed.
• Broader suite: 162 passed with four CocoaPods tests deselected; the two fully mocked CocoaPods tests also passed separately (164 passing tests total).
• Full suite attempted: test_cocoapods_packages failed with an SSL connection error fetching a podspec from raw.githubusercontent.com; the run was interrupted when the following live-network CocoaPods test stalled. Those two tests are unchanged by this PR. Related existing issue: Some unit tests depends on external services #188.
• make check passed (pycodestyle, isort, Black).
• git diff --check passed.
• Python 3.12.3 on Linux. Remote CI is pending.

Checklist

• I understand the problem and implemented the solution using appropriate functions.
• I added or updated tests to cover my changes.
• I verified my changes by running linting, ensuring all local tests pass, and confirming that CI checks succeed.

The final checkbox remains open because of the live-network test limitation above and pending CI. This change was prepared with Codex assistance.