community/eza: drop call to `cargo update`

While looking at the uses of cargo update in aports, I've found that the recipe for eza updates the time crate, supposedly to fix an incompatibility with newer versions of Rust.

This fix shouldn't be necessary anymore, as newer versions of eza already ship with a newer locked version of time. Also, cargo update without --precise makes cargo pick the latest semver-compatible version of the specified dependency, so this breaks reproducibility as the exact version varies depending on the time at which the package was built.