SkiaSharp upgrade

[Cairn23]

Problem / motivation

SkiaSharp has updated the version and the frequency of updates to match Google and Skia to approx. fortnightly.
The latest version of SkiaSharp is 4.148.
There is a large performance update with version 4, and this will improve once Graphite work has completed.

Proposed solution

Update the nugget packages to the latest versions of SkiaSharp. This may also have to include MapSui

Affected area

Renderers (Skia / Mapsui)

Alternatives considered

No response

Spec references (optional)

No response

Additional context

No response

[philliphoff]

@Cairn23 I saw the announcement yesterday and am eager to upgrade, but I think we have to wait for Mapsui to adopt the newer version before we can ourselves. Mapsui only recently added support for Avalonia UI 12, which allowed us to finally adopt that update, so we may have to wait a bit.

[philliphoff]

It looks like the blocker is Avalonia UI itself; it needs to move to SkiaSharp 4 before Mapsui can do so (though there seems to be a way it can reference the latest 3.9.x release that allows clients to roll forward to 4). That said, a consequence of this move would be dropping .NET 8 for the S100.

[Cairn23]

Dropping .net core 8 I cannot see as a big problem as it goes out of support in just over 3 months, so if that is the blocker I would get that done now in pre for the Mapsui move as soon as it comes out

[philliphoff]

@Cairn23 I don't have a problem dropping .NET 8 when it's out of support, and then probably adding 11 support at the same time. Both should be a minimal change.