build(deps): Bump ReactiveUI.Validation from 2.2.1 to 3.0.1 in /src (#81)

Bumps [ReactiveUI.Validation](https://github.com/reactiveui/reactiveui.validation) from 2.2.1 to 3.0.1.
- [Release notes](https://github.com/reactiveui/reactiveui.validation/releases)
- [Commits](https://github.com/reactiveui/reactiveui.validation/compare/2.2.1...3.0.1)

---
updated-dependencies:
- dependency-name: ReactiveUI.Validation
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/Avalonia.NameGenerator.Sandbox/Avalonia.NameGenerator.Sandbox.csproj

@@ -20,6 +20,6 @@
         <ProjectReference Include="..\Avalonia.NameGenerator\Avalonia.NameGenerator.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
     </ItemGroup>
     <ItemGroup>
-      <PackageReference Include="ReactiveUI.Validation" Version="2.2.1" />
+      <PackageReference Include="ReactiveUI.Validation" Version="3.0.1" />
     </ItemGroup>
 </Project>