New sources and better rust support
- add support for savannah hosted projects. thanks to @schnusch
- add support for sourcehut hosted projects, thanks to @SuperSandro2000
- add support for updating cargoHash, thanks to @SuperSandro2000
- In nixpkgs, nix-update now ignores local overlays, thanks to @SuperSandro2000
- cargo hashes and go vendor hashes cannot be updated even if the version has not changed