Do we want to have a rust-toolchain.toml file in the repo?

Currently, this repo has a rust-toolchain.toml file in it, pinning the version to 1.75.0: https://github.com/oxidecomputer/usdt/blob/d4b8090f2bf8527bf6aa0c43e94063ee68647c41/rust-toolchain.toml#L1 Is this something we'd still like to carry around? * For binaries it makes sense to have such a file, but usdt is primarily a library. * usdt needed nightly features for a long time, but it no longer does (and #267 removes all the nightly code). * Rust is "append-only" and new versions very rarely break old code. Would it make sense to remove the rust-toolchain.toml file, and let CI find issues with the MSRV?