Bump CommunityToolkit.Mvvm from 8.3.2 to 8.4.0

Bumps [CommunityToolkit.Mvvm](https://github.com/CommunityToolkit/dotnet) from 8.3.2 to 8.4.0.
- [Release notes](https://github.com/CommunityToolkit/dotnet/releases)
- [Commits](CommunityToolkit/dotnet@v8.3.2...v8.4.0)

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

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

source/dotRMDY.Components.MvvmCross/dotRMDY.Components.MvvmCross.csproj

@@ -14,7 +14,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="CommunityToolkit.Mvvm" Version="8.3.2" />
+        <PackageReference Include="CommunityToolkit.Mvvm" Version="8.4.0" />
         <PackageReference Include="JetBrains.Annotations" Version="2024.3.0" PrivateAssets="All" />
         <PackageReference Include="MvvmCross" Version="9.2.0"/>
     </ItemGroup>