Adapt to new python-tuf repository module

[dennisvang]

The recently released python-tuf v2.1.0 introduces an experimental repository package.

(UPDATE: still experimental in python-tuf v3.0.0)
(UPDATE: still experimental in python-tuf v3.1.0)

This is not part of python-tuf's stable API yet, but, as soon as it does become stable, we should replace our custom repository tools by those from python-tuf (as far as possible).

As mentioned in #9, we should use standard tools from python-tuf as much as possible.

[jku]

This is not part of python-tuf's stable API yet, but, as soon as it does become stable, we should replace our custom repository tools by those from python-tuf (as far as possible).

It's not "unstable" because we expect it to change... The main reason it's not marked stable is that so far I've been the only user (in tuf-on-ci)... I'd really love to get someone else using the API in anger. Figuring out a useful api for this was really hard -- I'm still not sure if the design is actually generic and works for other apps or not.

I'm also ready to have a video chat about the whole thing, and talk about features you might need, or show how I'm using it in tuf-on-ci if that would help.

[dennisvang]

@jku Thanks, that's good to know. I was actually waiting for a "stable" version before diving in.

... I'd really love to get someone else using the API in anger. ...

I'd love to help, so I'll start by taking a closer look at tuf.repository (and tuf-on-ci) to see how it works.

I'm also ready to have a video chat about the whole thing, and talk about features you might need, or show how I'm using it in tuf-on-ci if that would help.

That would be great, although I would need some time to play around with the repository module first, so I'll know what it's about.