Reduce Result<Tok, LexicalError> size by using Box<str> instead of String

[MichaReiser]

• Reduce the LexicalError type by using Box<str> over String
• Reduce the Tok size by using Box<str> over String.

Using Box<str> is sufficient for us because we don't want to mutate the error message or token value.

The downside of this is that using Box<str> is slightly more annoying.

Future: It would be interesting to change the Lexer signature always to return a Tok::Invalid and write the errors to a Vec instead. This should allow for drastically reducing the size of Tok and Spanned.

[codspeed-hq]

CodSpeed Performance Report

Merging #9885 will not alter performance

_{Comparing reduce-tok-size (7a7f01c) with main (9027169)}

Summary

✅ 30 untouched benchmarks

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

Formatter (stable)

✅ ecosystem check detected no format changes.

Formatter (preview)

✅ ecosystem check detected no format changes.

[BurntSushi]

Nice!!!

[charliermarsh]

I'm not kidding I was thinking about this as I fell asleep a few nights ago.