Support SourceForge (sourceforge.net) repositories

[lcarva]

Summary

Add support for resolving and verifying packages hosted on SourceForge (sourceforge.net).

Packages

Package	Version	Repository
ruamel-yaml	0.19.1	https://sourceforge.net/p/ruamel-yaml/code

Notes

SourceForge supports multiple VCS backends (git, hg, svn). The repository URL structure and archive download mechanism varies by project. SourceForge has a REST API, but git-based approaches (e.g., git ls-remote, git clone) may be more reliable for projects using git.