lib64gdiplus0-2.10.9-6.mga4 provides /usr/lib64/libgdiplus.so.0 and /usr/lib64/libgdiplus.so.0.0.0.
However, the mono runtime when using -pkg:dotnet is looking for libgdiplus.so. I solved it by manually creating a symlink from libgdiplus.so.0.0.0 to libgdiplus.so, but it would be nice if the package could be updated to add the link.