This is done in a hacky way, mostly to keep it simple and avoid having
to do a refactoring of the `EditorExportPlatform` interface.
Only Windows and Linux use `EditorExportPlatformPC`, and thus to
handle the new architectures for Linux, we simply do a few checks here
and there with a couple new methods to register the export template
names for Linux arm64 and arm32.
For Godot 4.0, we did refactor everything to allow exporting binaries
for different architectures cleanly. For 3.6, which is likely the last
feature release for the 3.x branch, I tend to cut corners as these
improvements will be shorter lived and thus new tech debt isn't as big
a concern.
