Drop workspace-hack in favor of workspace deps

Workspace deps were introduced in Rust 1.64. They don't cover all the
cases that Hakari did unfortunately, but they are simpler to maintain,
and they avoid a couple of issues that Hakari had:

- It sometimes made updating dependencies harder due to the locked versions,
so you had to disable Hakari, do the updates, and then re-generate (
e.g. 943dddf)
- The current Hakari config was breaking AnkiDroid's build, as it was
stopping a cross-compile from functioning correctly.