I've just requested a git-bare bundle for the latest snapshot via their API. It should contain all branches and releases in a bare Git repository which can be used to reconstruct the repository. It'll take a bit, but you can see the progress here:

https://archive.softwareheritage.org/api/1/vault/git-bare/sw...

Once it's finished, it should be available at:

https://archive.softwareheritage.org/api/1/vault/git-bare/sw...