Since Embree v3.13.0 supports AARCH64, switch back to the
official repo instead of using Embree-aarch64.
`thirdparty/embree/patches/godot-changes.patch` should now contain
an accurate diff of the changes done to the library.
(cherry picked from commit 767e374dce)
Fixes#45687.
This is really just a band-aid, our current buildsystem doesn't work well for
cross-compilation and needs a thorough refactoring to do so.
