Prefer const/statics when possible

[burdges]

I learned about this create from https://users.rust-lang.org/t/ron-are-there-crates-to-serialize-rust-types-as-correctly-formated-rust-code/55451

Could one prefer const/static forms when they exist?

As a type level example, if T could be converted to 'static then Cow<'a,T> should be replaced by Cow<'static,T>.

As a value level, both Cow::Owned(Box<[T]>) and Cow::Borrowed(&'a [T]) should be replaced by Cow::Borrowed(&'static [T]).

There might exist users who'd wish to forbid allocations like Vec<T> etc. entirely too, but almost anyone using uneval should replace String with Cow<'static,str> and replace Vec<T> with Cow<'static,[T]>.

[burdges]

Appears you serialize all allocated types with vec![..].into_iter().collect(), which should probably be &'static [..].into_iter().collect().

It appears serde fully dereferences any Deref types, so Cow breaks uneval: https://github.com/burdges/uneval/blob/cow/examples/cow_test.rs