Switch to `git` protocol for CI dependencies
Switch to `git` protocol for CI dependencies

If you try to clone a repo that doesn't exist via `https`, `git` will prompt for
auth credentials and hang forever. Using `git` avoids this and fails immediately
instead, which is what we want for a missing repo.

Part of https://github.com/vector-im/riot-web/issues/9221

vector-im/vector-web,vector-im/riot-web,vector-im/riot-web,vector-im/riot-web,vector-im/riot-web,vector-im/vector-web,vector-im/vector-web,vector-im/riot-web,vector-im/vector-web,vector-im/riot-web,vector-im/vector-web