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)
- Fix Embree runtime when using MinGW (patch by @RandomShaper).
- Fix baking of lightmaps on GridMaps.
- Fix some GLSL errors.
- Fix overflow in the number of shader variants (GLES2).