Diagnostics for full solution do not work

## Issue Description

Modify dotnet.backgroundAnalysis.compilerDiagnosticsScope to "fullSolution", but only show openFiles

project state

"dotnet.server.useOmnisharp": false,


"dotnet.server.useOmnisharp": true,


## Environment data
`dotnet --info` output:

[dotnet info.txt](https://github.com/user-attachments/files/20653161/dotnet.info.txt)

VS Code version: 1.100.3
C# Extension version: 2.80.16

## C# logs

[c# load project.log](https://github.com/user-attachments/files/20653162/c.load.project.log)

[c# open file.log](https://github.com/user-attachments/files/20653164/c.open.file.log)

[c# close file.log](https://github.com/user-attachments/files/20653165/c.close.file.log)

[C# LSP.log](https://github.com/user-attachments/files/20653167/C.LSP.log)

## Steps to reproduce

[TestConsole.zip](https://github.com/user-attachments/files/20653123/TestConsole.zip)

## Expected behavior

https://github.com/user-attachments/assets/06b63b1e-22da-49ef-b38b-ebe2936e6f96

## Actual behavior

https://github.com/user-attachments/assets/4f143dfd-4e77-4c40-ac32-25c7826bc022