Prepare for SkiaSharp 3.0.0

[taublast]

Hi, do you plan on preparing for SkiaSharp 3.0 in advance by starting to support 3.0.0-preview.4.1?
In theory the stable 3.0 is "for the end of the year" so..

[inforithmics]

This is the pull request #2603, when Skiasharp gets stable than this will be merged.
Most incompatibilites have been fixed in the latest mapsui preview so simple using mapsui Preview with nightly skiasharp should work.
see here mono/SkiaSharp#2999
nightly skiasharp
https://pkgs.dev.azure.com/xamarin/public/_packaging/SkiaSharp/nuget/v3/index.json

[inforithmics]

Version 3.0.0-preview.5.4 of SkiaSharp is released so everything should work now. Waiting for Release