Migrate to Rust 2024 Edition

The Rust 2024 edition is being stabilized in the next two days, according to the document (https://doc.rust-lang.org/nightly/edition-guide/rust-2024/index.html). Although we have three months until the official release date, we should consider migrating to the edition.

The biggest issue is that the static mut is marked as denied by default in the edition.