Bump ReactiveUI from 15.1.1 to 16.1.1 in /src (#835)

Bumps [ReactiveUI](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
  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/Whipstaff.AspNetCore/Whipstaff.AspNetCore.csproj

@@ -30,7 +30,7 @@
     <PackageReference Include="Microsoft.FeatureManagement.AspNetCore" Version="2.3.0" />
     <PackageReference Include="Microsoft.VisualStudio.Web.BrowserLink" Version="2.2.0" />
     <PackageReference Include="MiniProfiler.AspNetCore.Mvc" Version="4.2.22" />
-    <PackageReference Include="ReactiveUI" Version="15.1.1" />
+    <PackageReference Include="ReactiveUI" Version="16.1.1" />
     <PackageReference Include="OwaspHeaders.Core" Version="4.2.0" />
     <PackageReference Include="RimDev.ApplicationInsights.Filters" Version="1.1.52" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.1.5" />