Bump SkiaSharp from 2.88.3 to 2.88.6 in /src/Mobile

Bumps [SkiaSharp](https://github.com/mono/SkiaSharp) from 2.88.3 to 2.88.6.
- [Release notes](https://github.com/mono/SkiaSharp/releases)
- [Commits](https://github.com/mono/SkiaSharp/compare/v2.88.3...v2.88.6)

---
updated-dependencies:
- dependency-name: SkiaSharp
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

src/Mobile/Microsoft.NetConf2021.Maui.csproj

@@ -65,7 +65,7 @@
     <PackageReference Include="CommunityToolkit.Mvvm" Version="8.0.0" />
     <PackageReference Include="MonkeyCache.FileStore" Version="2.0.0-beta" />
     <PackageReference Include="Refractored.MvvmHelpers" Version="1.6.2" />
-    <PackageReference Include="SkiaSharp" Version="2.88.3" />
+    <PackageReference Include="SkiaSharp" Version="2.88.6" />
     <PackageReference Include="System.Threading.RateLimiting" Version="7.0.0" />
   </ItemGroup>