[bug] 0.20 has lost support for numerous code actions on projects targeting .NET <10

Previously, on dotnet 8 and csharp-ls v0.19, you'd see the full list of code actions. This has been shrunk down to this:

<img width="1074" height="664" alt="Image" src="https://github.com/user-attachments/assets/e3601b16-30fe-4049-a7bc-02015c98c603" />

from this:

<img width="1101" height="699" alt="Image" src="https://github.com/user-attachments/assets/85ca67c6-3f9b-4de3-b5a2-fb503fb51c83" />