Godot addon: Linter: The background color of linted lines disappear if the script is edited

## Description
- Using GDScript formatter 0.18.2 with Godot 4.6 on Windows
- On linting a file, problematic lines are colored in red or yellow to indicate a linter error or warning. These colors disappear within 1-2 seconds of editing the script in Godot script editor (even without saving the file).

## Reproduce
- Write a script with a linter issue :
```gdscript
func _init() -> void:
print("hello")
pass # <- this produces a linter warning (unnecessary-pass)
```
- Lint it (Ctrl+S or Format > Lint Current Script). The `pass` line is now colored in yellow.
- Edit it (you can just add a new line, or edit the comment).

## Expected behaviour
- The `pass` line coloration do not change.

## Observed behaviour
- The `pass` line coloration disappear after 1-2 seconds.

## Additional informations
This behaviour can be indirectly triggered by saving the script, because saving the script can trigger the formatting and edit the script.

Also: Godot seems to redraw the script editor if the script is edited, then left unedited for 1-2 seconds. I believe this is the cause of this behaviour.

Reproduisez le problème dans Godot 4.6 avec GDScript formatter 0.18.2 en faisant le linting d’un script dans l’éditeur de scripts de Godot, en le modifiant, puis en attendant le redessin. Suivez le comportement de la mise en évidence du lint autour du point d’entrée Format > Lint Current Script ; c’est terminé lorsque les couleurs de lint rouge et jaune restent visibles après la modification et le redessin différé.

Rédigé par le modèle d'indexation à partir du texte de l'issue.