Systemd & WindowsServices in Microsoft.Extensions.Hosting are missing in .NET 5, 6, 7 docs

The docs for types and members in `Microsoft.Extensions.Hosting.[Systemd|WindowsServices]` stopped getting tagged as available in current .NET after [having been moved from the Extensions repo](https://github.com/dotnet/runtime/pull/47686/files).

See for example: https://docs.microsoft.com/en-us/dotnet/api/microsoft.extensions.hosting.systemdhostbuilderextensions?view=dotnet-plat-ext-6.0, showing a banner:

> The requested page is not available for .NET Platform Extensions 6. You have been redirected to the newest product version this page is available for.

Even though the class has been in .NET since .NET Core 3.0. I [made a PR adding those versions](https://github.com/dotnet/dotnet-api-docs/pull/8141/files), but got a reply from @gewarren stating:

> It looks like the packages are missing from [this file](https://github.com/dotnet/api-catalog-infra/blob/main/eng/droplayout.props), which is why the documentation hasn't been updated. @carlossanlop Can you look into this and generate a new drop if necessary (or just wait until the Preview 5 drop is generated)?

Since that's a nonpublic repo, can you look into fixing that?

Then, an additional question regarding these Platform Extensions: in which directory should the file `WindowsServiceLifetimeHostBuilderExtensions.xml` reside, describing a type in the assembly `Microsoft.Extensions.Hosting.WindowsServices`:
* `xml/Microsoft.Extensions.Hosting`, where it's now, according to its namespace, or
* `xml/Microsoft.Extensions.Hosting.WindowsServices`, according to its assembly name and source location?

I ask this because the dependency injection extension method (`services.UseWindowsService()`) is now documented under "Microsoft.Extensions.Hosting", while for example the lifetime (`WindowsServiceLifetime`) is documented under "Microsoft.Extensions.Hosting.WindowsServices".