🤖 Bump MaterialDesignThemes from 3.2.0 to 4.0.0 (#3115)

Bumps [MaterialDesignThemes](https://github.com/MaterialDesignInXAML/MaterialDesignInXamlToolkit) from 3.2.0 to 4.0.0.
- [Release notes](https://github.com/MaterialDesignInXAML/MaterialDesignInXamlToolkit/releases)
- [Commits](https://github.com/MaterialDesignInXAML/MaterialDesignInXamlToolkit/compare/v3.2.0...v4.0.0)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Shadowsocks.WPF/Shadowsocks.WPF.csproj

@@ -49,7 +49,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="MaterialDesignThemes" Version="3.2.0" />
+    <PackageReference Include="MaterialDesignThemes" Version="4.0.0" />
     <PackageReference Include="MdXaml" Version="1.9.0" />
     <PackageReference Include="OxyPlot.Wpf" Version="2.0.0" />
     <PackageReference Include="ReactiveUI.Events.WPF" Version="13.1.1" />