v0.3.7

• Small release to fix an issue with 0.3.6 being published with invalid local changes (I thought cargo prevented this, dunno how it happened)
• Mark functions on Interval and Grad as #[inline], to improve performance when those types are used outside of the Fidget crate itself.
• Make fidget::rhai submodules visible (vec, shape, tree) for finer-grained usage outside of Fidget.
• Update to Rust 2024 edition, set minimum rustc version to 1.87
• Update dependencies; remove some that have become unused