fix integration test app, missing inter font package.

samples/IntegrationTestApp/IntegrationTestApp.csproj

@@ -19,6 +19,7 @@
   <ItemGroup>
     <ProjectReference Include="..\..\src\Avalonia.Diagnostics\Avalonia.Diagnostics.csproj" />
     <ProjectReference Include="..\..\src\Avalonia.Themes.Fluent\Avalonia.Themes.Fluent.csproj" />
+    <ProjectReference Include="..\..\src\Avalonia.Fonts.Inter\Avalonia.Fonts.Inter.csproj" />
   </ItemGroup>
   
   <Import Project="..\..\build\BuildTargets.targets" />