Bump System.Reactive from 4.0.0-preview00001 to 5.0.0 in /AsyncRx.NET

Bumps [System.Reactive](https://github.com/dotnet/reactive) from 4.0.0-preview00001 to 5.0.0.
- [Release notes](https://github.com/dotnet/reactive/releases)
- [Commits](https://github.com/dotnet/reactive/commits/ixnet-v5.0.0)

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

AsyncRx.NET/ApiCompare/ApiCompare.csproj

@@ -6,7 +6,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="System.Reactive" Version="4.0.0-preview00001" />
+    <PackageReference Include="System.Reactive" Version="5.0.0" />
   </ItemGroup>
 
   <ItemGroup>