overhaul deps

[alerque]

Closes #68 — or will once these changes land in a release.

This does a number of things to overhaul the dependency situation. First it fixes the lock file so that the app can be built at all, and testing can be done to show that it works in that state. Then it systematically works through figuring out what the current status quo MSRV is, saves it properly in the manifest, then updates the lock file again to bump patch level versions of dependencies. Thet it deals with Clippy stuff to get a clean bill of health (both currenth 1.91.0 and at the MSRV) and then works through updating the major version bumps to some dependencies, including fixing the code to work with new APIs.

Note that this still has an ancient version of the git2 crate, but that's because it needs to match the version upstream in git-graph. Updating that will require first making API changes in git-graph, releasing those changes, then updating it here.

Please don't squash these commits.

[alerque]

(BTW I'm working on CI updates separately from this PR because testing them is going to be a bit tricker and the merge concerns are a bit different. Expect a draft PR soon where I can hopefully check the status of pipelines without waiting for somebody to trigger them. As of right now iterating on that is going to be hard, but if this merges and the CI restriction is for first time contributors only that should clear up.)

[peso]

Looks good