How can we performe a cargo update for the cargo install command?
There is no such command in vanilla cargo (well, there's cargo install but that's for dependencies), but since cargo supports third-party subcommands there is an answer: the cargo-update crate.
Install as usual with:
cargo install cargo-update
then use
cargo install-update -a
To update all installed packages, for more usage information and examples see the cargo install-update man page.