Xueqin Cui

Add documentation for `update` subcommand

1

There is no documentation for the experimental `update` subcommand.

Mock clients for testing

1

We now rely on real data for testing and this causes us updating snapshots quite often. Considering the work for interfaces and clients are done, we can implement mock clients...

This is not covered in the workflow yet...

Currently, OSV-Scanner depends on [`requirementsnet` extractor](https://github.com/google/osv-scalibr/tree/main/extractor/filesystem/language/python/requirementsnet) for transitive extraction for `requirements.txt`. However, OSV-Scalibr is migrating to use [`transitivedependency` enricher](https://github.com/google/osv-scalibr/tree/main/enricher/transitivedependency/requirements) for this purpose. We probably should migrate [`requirementsenhancable`](https://github.com/google/osv-scanner/tree/main/internal/scalibrextract/language/python/requirementsenhancable) to use the...

We now rely on osv-schema for vulnerability.proto so we may need to regenerate protobuf code if osv-schema is updated.