Bump Extended.Wpf.Toolkit from 4.5.1 to 4.6.0

Bumps [Extended.Wpf.Toolkit](https://github.com/xceedsoftware/wpftoolkit) from 4.5.1 to 4.6.0.
- [Release notes](https://github.com/xceedsoftware/wpftoolkit/releases)
- [Commits](xceedsoftware/wpftoolkit@4.5.1...4.6.0)

---
updated-dependencies:
- dependency-name: Extended.Wpf.Toolkit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

KaxamlPlugins/KaxamlPlugins.csproj

@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Extended.Wpf.Toolkit" Version="4.5.1" />
+    <PackageReference Include="Extended.Wpf.Toolkit" Version="4.6.0" />
     <PackageReference Include="ICSharpCode.TextEditor" Version="3.2.1.6466" />
   </ItemGroup>