build(deps): bump System.Reactive from 5.0.0 to 6.0.1

Bumps [System.Reactive](https://github.com/dotnet/reactive) from 5.0.0 to 6.0.1.
- [Release notes](https://github.com/dotnet/reactive/releases)
- [Commits](dotnet/reactive@ixnet-v5.0.0...ixnet-v6.0.1)

---
updated-dependencies:
- dependency-name: System.Reactive
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Directory.Packages.props

@@ -48,7 +48,7 @@
         <PackageVersion Include="System.Linq.Async" Version="6.0.1" />
         <PackageVersion Include="System.Memory" Version="4.5.5" />
         <PackageVersion Include="System.Private.Uri" Version="4.3.2" />
-        <PackageVersion Include="System.Reactive" Version="5.0.0" />
+        <PackageVersion Include="System.Reactive" Version="6.0.1" />
         <PackageVersion Include="System.Runtime.Loader" Version="4.3.0" />
         <PackageVersion Include="System.Text.Json" Version="7.0.3" />
         <PackageVersion Include="System.Threading.Channels" Version="6.0.0" />