

If you don’t have an Intel CPU, then you shouldn’t need it. At least, I think it’s only for CPUs and not for other intel-based devices (NIC, graphics, whatever).
It’s prompting for upgrade because it’s already installed. It’s recommended (but not required) by initramfs-tools, so that’s probably why it’s installed (recommended packages are installed by default). oops, read that wrong. Intel-microcode recommends initramfs-tools.
You may want to run
apt-rdepends intel-microcode
to see what pulled it in.
But you should be able to uninstall it, and then it won’t prompt you any more.
My toes, Sis.