SkiaSharp Native library for arm32 and arm64.

The 64-bit build runs with -flax-vector-conversions so, use at your own risk. Upstream issue: https://skia-review.googlesource.com/c/skia/+/84222 GCC seems to not support this.

Build (Debian based) (Also WSL)

1. cross-compile-libSkiaSharp.sh
2. mkdir -p ./runtimes/linux-arm/native && mkdir -p ./runtimes/linux-arm64/native
3. cp skia/out/linux-arm/libSkiaSharp.so ./runtimes/linux-arm/native/ && cp skia/out/linux-arm64/libSkiaSharp.so ./runtimes/linux-arm64/native/
4. nuget pack

Build (non Debian) (uses docker)

1. build-in-docker.sh
2. nuget pack