WezTerm with vertical (side) tab bar — Nix flake; based on #3537 / PR #7574

deps: cargo cooldown update master

Add a trivial little script to run `cargo cooldown update`. The purpose of the script is to make it a little more discoverable in the future if I or someone else forgets how this works. https://crates.io/crates/cargo-cooldown is required to run this script. Its purpose is to run `cargo update` while respecting the dependency cooldown options found in cooldown.toml in the root of the repo