This reintroduces lazy lfs file rules that were removed in
https://github.com/github/codeql/pull/16117, now improved.
The new rules will make the actual file download go through bazel's
download manager, which includes:
* caching into the repository cache
* sane limiting of concurrent downloads
* retries
The bulk of the work is done by `git_lfs_probe.py`, which will use the
LFS protocol (with authentication via SSH) to output short lived
download URLs that can be consumed by `repository_ctx.download`.
Paolo Tranquilli