[Enhancement] Auto update systemd-boot after a systemd update

[oneover0]

describe the request

By default archinstall script does not enbale the service to auto update systemd bootloader after a systemd update as mentioned here. Those who know can do this after a install but adding it would be good.

From Arch wiki

Note: The UEFI boot manager is a standalone EFI executable and any version can be used to boot the system (partial updates do not apply, since pacman only installs the systemd-boot installer, not systemd-boot itself.) However, new versions may add new features or fix bugs, so it is probably a good idea to update systemd-boot.

[JTEpic]

This is a feature that should not be on by default, but available in an optional category in archinstall.

The user must know what they are enabling as auto updating the boot loader can a cause system lock, especially with secure boot on.

[Torxed]

Good input, I think we can re-visit defaulting this to on once we have our signing enclave that can sign a shim for secure boot.

I've been wanting to add a "optimization" sub-menu for various things that are in theory "post-install" things but they're so common and minor that maintaining it would be trivial.