Currently, code serve-web seems to always grab the latest release for the client. This is convenient, but occasionally there are problems with the latest client using code serve-web leaves no way to downgrade or pin to a working client version. A flag like --commit-id would be a convenient escape hatch for these situations where we just need a way to temporarily avoid the latest release.

(This request was in particular inspired by #251731 as it would cause the client to crash upon opening certain notebooks)