The status of the editorconfig file is unedited after modifying the .editorconfig file

[jmarolf]

More info:
The issue doesn't happen when you create a project, then add and modify .editorconfig(.net) file

Steps to reproduce:

1. Clone repo: https://github.com/dotnet/project-system.git on git cmd
2. Open ProjectSystem.sln with VS
3. Add .editorconfig(.net) item on Microsoft.VisualStudio.ProjectSystem.Managed.CommonFiles project
4. Change value the .editorconfig file, then observe the file status
5. Close and reopen the .editorconfig file
6. Observe value of .editorconfig file

Actual result:
Step4 result: The status of the .editorconfig file is unedited
Step6 result: The value of the .editorconfig file don't change successfully

[Youssef1313]

This is the same as #60232 and point 7 in #53171

[Youssef1313]

Also #54556 and #56676

[jmarolf]

duplicate of #54556