Bump ReactiveUI.Fody from 15.1.1 to 16.1.1 (#23)

Bumps [ReactiveUI.Fody](https://github.com/reactiveui/reactiveui) from 15.1.1 to 16.1.1.
- [Release notes](https://github.com/reactiveui/reactiveui/releases)
- [Commits](reactiveui/ReactiveUI@15.1.1...16.1.1)

---
updated-dependencies:
- dependency-name: ReactiveUI.Fody
  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/Citrus.Avalonia.Sandbox/Citrus.Avalonia.Sandbox.csproj

@@ -13,7 +13,7 @@
     <PackageReference Include="Avalonia.LinuxFramebuffer" Version="0.10.7" />
     <PackageReference Include="Avalonia.Desktop" Version="0.10.7" />
     <PackageReference Include="ReactiveUI.Validation" Version="2.1.1" />
-    <PackageReference Include="ReactiveUI.Fody" Version="15.1.1" />
+    <PackageReference Include="ReactiveUI.Fody" Version="16.1.1" />
   </ItemGroup>
 
   <ItemGroup>