#15 JNBullet does not have Mac aarch64 target

[asotona]

resolves #15

[skaldarnar]

I got the chance to test these changes and building the lib on an M1 Mac via the following steps:

git submodule update --init --recursive

cd build
cmake ../ -DCMAKE_TOOLCHAIN_FILE=../toolchains/macosx_aarch64_clang.cmake
make

cd -
./gradlew native_macosx_aarch64_clang

The builds were successful and I've got an libbullet-darwin-aarch64.dylib in the end.

Next step would be piecing this together with Terasology to check where we stand with MovingBlocks/Terasology#5055.