Turbopack: Make `turbo-tasks-memory` crate Rust 2024 (#79130)
Isolated `cargo fmt` changes into their own commit. Please review the
first commit for core changes.
- `gen` is now a reserved word
- Marked `get_event_description_static` and `get_event_description` as
`'static`
- Marked `handle_new_edge` as `use<C>`
