maui: .NET8 - UseMauiEssentials not working on project targeting net6.0

Description

I updated Visual Studio 22 Windows to Version 17.8. This has installed the .NET8 SDK on my system.

A class library that includes <UseMauiEssentials> does not build.

Severity	Code	Description	Project	File	Line	Suppression State
Error	CS0103	The name 'Connectivity' does not exist in the current context
Error	CS0234	The type or namespace name 'Maui' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?)

I am then told the solution is to install the Xamarin.Essentials package which is not compatible with any .NET SDK project.

The project builds if:

• I create a global.json and point to .NET7 or .NET6 SDKs (which had to be reinstalled as it seems .NET8 nukes those upon install)
• I change the target project to net7.0

Steps to Reproduce

1. Create a new class library targeting net6.0
2. Edit project file to look like:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
      <UseMauiEssentials>true</UseMauiEssentials>
  </PropertyGroup>
</Project>

1. Add the following code to Class1.cs

using Microsoft.Maui.Networking;
namespace MauiEssentialBug {
    public class Class1 {
        public void Foo()  {
            var x = Connectivity.NetworkAccess;
            System.Diagnostics.Debug.WriteLine($"Foo = {x}");
        }
    }
}

1. Fails to compile

Link to public reproduction project repository

https://github.com/projectgoav/MauiEssentialsBug

Version with bug

Unknown/Other

Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

Last version that worked well

Unknown/Other

Affected platforms

Android, Windows

Affected platform versions

.NET8 / VS22 17.8

Did you find any workaround?

Upgrading the project to net7.0 Adding a global.json to point to .NET7 SDK

Relevant log output

No response