build(deps): bump Microsoft.NET.Test.Sdk from 17.8.0 to 17.9.0

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 17.8.0 to 17.9.0.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Changelog](https://github.com/microsoft/vstest/blob/main/docs/releases.md)
- [Commits](microsoft/vstest@v17.8.0...v17.9.0)

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

src/Projektanker.Icons.Avalonia.FontAwesome.Test/Projektanker.Icons.Avalonia.FontAwesome.Test.csproj

@@ -6,7 +6,7 @@
     <ItemGroup>
         <PackageReference Include="Avalonia.Skia" Version="11.0.2" />
         <PackageReference Include="FluentAssertions" Version="6.12.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
         <PackageReference Include="xunit" Version="2.6.6" />
         <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

src/Projektanker.Icons.Avalonia.MaterialDesign.Test/Projektanker.Icons.Avalonia.MaterialDesign.Test.csproj

@@ -6,7 +6,7 @@
     <ItemGroup>
         <PackageReference Include="Avalonia.Skia" Version="11.0.2" />
         <PackageReference Include="FluentAssertions" Version="6.12.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
         <PackageReference Include="xunit" Version="2.6.6" />
         <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

src/Projektanker.Icons.Avalonia.Test/Projektanker.Icons.Avalonia.Test.csproj

@@ -7,7 +7,7 @@
 
     <ItemGroup>
         <PackageReference Include="FluentAssertions" Version="6.12.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
         <PackageReference Include="NSubstitute" Version="5.1.0" />
         <PackageReference Include="xunit" Version="2.6.6" />
         <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">