There are no other projects in the solution to add a reference to in Explorer if closing solution in SE view

Describe the Issue

There are no other projects in the solution to add a reference to in Explorer if closing solution in SE view.

Steps To Reproduce

1.Create a C# Console App and add any project such as WebApplicationMVC to the less-solution.
2.Close the solution in SE view.
3.In the Explorer, right click the ConsoleApp.csproj or WebApplicationMVC.csproj->Add Project Reference and observe.
4.Compare in Solution Explorer: Open the solution in SE, try to add project reference for the projects again and observe.

Expected Behavior

It is possible to add project references in Explorer.

Environment Information

.NET Install Tool: Pre-release 3.0.0
C# Dev Kit Extension: Pre-release 2.13.9
C# Extension: Pre-release 2.123.34
.NET SDKs:  11.0.100-preview.1.26104.118
VSCode Stable: 1.109.5
Platform: Windows X64 

Start by reproducing the issue in VS Code Explorer with the listed Console App and WebApplicationMVC projects, then compare the Add Project Reference behavior with Solution Explorer when the solution is open. Done means Explorer exposes the other projects as selectable references after the solution is closed in SE view.