[Breaking] Update dependencies

[GnomedDev]

Gets rid of these ancient dep versions, sadly this doesn't fully kill syn 1 (which is my goal) due to the shorthand dep but I have opened an issue over there (although I'm a little concerned about it's usage, idiomatic Rust simply makes a field public instead of a getter/setter pair).

[sile]

LGTM. Thank you 👍

[sile]

although I'm a little concerned about it's usage, idiomatic Rust simply makes a field public instead of a getter/setter pair

That sounds reasonable.
At the moment, I'm not entirely sure that "making a field public" is the best approach for this crate.
However, I am open to reviewing a PR that removes the shorthand dependency (if you want).

[GnomedDev]

I was looking at removing the shorthand dep, but it's a major amount of work as it is used all over this library. Getters can be useful for read-only public access, but setters are only needed rarely when there are preconditions to be upheld.