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.