Bump CommunityToolkit.Mvvm from 8.0.0 to 8.1.0 (#3060)

* Bump CommunityToolkit.Mvvm from 8.0.0 to 8.1.0

Bumps [CommunityToolkit.Mvvm](https://github.com/CommunityToolkit/dotnet) from 8.0.0 to 8.1.0.
- [Release notes](https://github.com/CommunityToolkit/dotnet/releases)
- [Commits](CommunityToolkit/dotnet@v8.0.0...v8.1.0)

---
updated-dependencies:
- dependency-name: CommunityToolkit.Mvvm
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

* Fixing build warning

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Kevin Bost <[email protected]>

Author: dependabot[bot]

Directory.packages.props

@@ -1,7 +1,7 @@
 <Project>
   <ItemGroup>
     <PackageVersion Include="BluwolfIcons" Version="1.0.1" />
-    <PackageVersion Include="CommunityToolkit.Mvvm" Version="8.0.0" />
+    <PackageVersion Include="CommunityToolkit.Mvvm" Version="8.1.0" />
     <PackageVersion Include="Dragablz" Version="0.0.3.234" />
     <PackageVersion Include="Humanizer" Version="2.14.1" />
     <PackageVersion Include="MahApps.Metro" Version="2.4.9" />

MaterialDesignThemes.UITests/Samples/DialogHost/ClosingEventViewModel.cs

@@ -3,8 +3,7 @@
 
 namespace MaterialDesignThemes.UITests.Samples.DialogHost;
 
-[ObservableObject]
-public partial class ClosingEventViewModel
+public partial class ClosingEventViewModel : ObservableObject
 {
     [ObservableProperty]
     private bool _dialogIsOpen;