chore(deps): bump SkiaSharp.NativeAssets.NanoServer and SkiaSharp

Bumps [SkiaSharp.NativeAssets.NanoServer](https://github.com/mono/SkiaSharp) and [SkiaSharp](https://github.com/mono/SkiaSharp). These dependencies needed to be updated together.

Updates `SkiaSharp.NativeAssets.NanoServer` from 2.88.7 to 2.88.8
- [Release notes](https://github.com/mono/SkiaSharp/releases)
- [Commits](mono/SkiaSharp@v2.88.7...v2.88.8)

Updates `SkiaSharp` from 2.88.7 to 2.88.8
- [Release notes](https://github.com/mono/SkiaSharp/releases)
- [Commits](mono/SkiaSharp@v2.88.7...v2.88.8)

---
updated-dependencies:
- dependency-name: SkiaSharp.NativeAssets.NanoServer
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: SkiaSharp
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

samples/NanoServerGenerate60/NanoServerGenerate60.csproj

@@ -11,7 +11,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.19.6" />
-    <PackageReference Include="SkiaSharp.NativeAssets.NanoServer" Version="2.88.7" />
+    <PackageReference Include="SkiaSharp.NativeAssets.NanoServer" Version="2.88.8" />
   </ItemGroup>
 
   <ItemGroup>