Bump ReactiveUI.Fody and ReactiveUI

Bumps [ReactiveUI.Fody](https://github.com/reactiveui/reactiveui) and [ReactiveUI](https://github.com/reactiveui/reactiveui). These dependencies needed to be updated together.

Updates `ReactiveUI.Fody` from 19.5.1 to 19.5.39
- [Release notes](https://github.com/reactiveui/reactiveui/releases)
- [Commits](reactiveui/ReactiveUI@19.5.1...19.5.39)

Updates `ReactiveUI` from 19.5.31 to 19.5.39
- [Release notes](https://github.com/reactiveui/reactiveui/releases)
- [Commits](reactiveui/ReactiveUI@19.5.31...19.5.39)

---
updated-dependencies:
- dependency-name: ReactiveUI.Fody
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: ReactiveUI
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

ReactiveUISample/ReactiveUISample.csproj

@@ -4,8 +4,8 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Fody" Version="6.8.0" PrivateAssets="all" />
-    <PackageReference Include="ReactiveUI" Version="19.5.31" />
-    <PackageReference Include="ReactiveUI.Fody" Version="19.5.1" />
+    <PackageReference Include="ReactiveUI" Version="19.5.39" />
+    <PackageReference Include="ReactiveUI.Fody" Version="19.5.39" />
     <PackageReference Include="Xunit" Version="2.6.4" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />