Add an `update` command for updating noirup itself

[Savio-Sou]

Problem

New noirup features (e.g. installing noir-profiler) requires updating the noirup tool itself (e.g. to noirup v0.1.4).

The current way to update noirup is to reinstall the tool by calling curl -L https://raw.githubusercontent.com/noir-lang/noirup/main/install | bash, which requires the frictional step of revisiting docs and copying the command.

Happy Case

Add a new noirup update command that automatically reinstalls / updates noirup to the latest stable release.

Additional Context

To some degree similar to Rust's rustup update, difference being Rust's command also automatically updates Cargo but automatically updating Nargo is out of scope of this Issue.

Project Impact

Nice-to-have

Would you like to submit a PR for this Issue?

No