removed(hal)!: Remove embedded-hal v0.2 implementations

[jbeaurivage]

Summary

Finally, this was long overdue!

Checklist

• All new or modified code is well documented, especially public items
• No new warnings or clippy suggestions have been introduced - CI will deny clippy warnings by default! You may #[allow] certain lints where reasonable, but ideally justify those with a short comment.

[ianrrees]

This looks like exactly the sort of PR that would be good for testing #830 . I won't have much time to work on it in the next few days, but I'll try to rebase that branch that adds the example management program on to the current master, then maybe we try putting this work on top of it to see what the example update process would look like.