Format Bar does not revert to settings when not overridden by .editorconfig

### What Happened?

After editing a document where a tab width of "2" was set in `.editorconfig` (e.g. an .xml file) when switching to a file with no tab width was specified in `.editorconfig`, the tab width remained at "2" even though the app default setting was "4" (as determined by the value of `io.elementary.code.settings.indent-width`.

### Steps to Reproduce

1. Open a project whose `.editorconfig` file has no global specification for `tab_width` (e.g. Code itself)
2. Open an XML file and e.g. the `.editorconfig` file
3. Focus the XML document - the format button becomes insensitive with a value of "2" as expected
4. Focus the other file - the format button becomes sensitive, as expected, but the value remains at "2"

### Expected Behavior

Where the `editorconfig` does not specify a tab width for a file type, then the app default setting should be used if the file is empty or has no tab width set internally; if the file has a tab_width specified in its header or otherwise then that should be used. This should occur regardless of the previously focussed document.

### OS Version

7.x (Early Access)

### Software Version

Latest release (I have run all updates)

### Log Output

_No response_

### Hardware Info

_No response_

Commencez par suivre l’état de la largeur de tabulation de la Format Bar en parallèle de la gestion de .editorconfig, en utilisant les fichiers XML et .editorconfig des étapes de reproduction. Vérifiez le paramètre io.elementary.code.settings.indent-width lorsque le focus passe d’un fichier à l’autre ; le travail est terminé lorsqu’un tab_width non spécifié revient à la valeur par défaut de l’application, sauf si le fichier possède son propre tab_width.

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