foxotron: fetch assimp patches to fix build
Foxotron vendors a lot of dependencies (see the `external` directory and
the various submodules it contains). One of them (`FBX`) fails to build
with current versions of GCC because the compiler cannot resolve the
type `std::uint32_t`. The affected file still imports the type via
`#include <stdint.h>`, which has been superseded by `#include <cstdint>`
in C++11.
The upstream patch applied here fixes this build issue by introducing
the missing include line of `<cstdint>`.
The new addition to `postPatch` disables a `-Werror` setting that
(currently) seemingly only causes assimp builds failures on darwin.
Co-authored-by: Cosima Neidahl <opna2608@protonmail.com>
