SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
Verifying a Wii game creates an instance of IOS, and Dolphin
can't handle more than one instance of IOS at the same time.
Properly supporting it is probably more effort than it's worth.
Fixes https://bugs.dolphin-emu.org/issues/12494.