Update novelwriter/gui/mainmenu.py

added above def updateSpellCheckLanguages(self) -> None:
    @pyqtSlot()

Co-authored-by: Veronica Berglyd Olsen <1619840+vkbo@users.noreply.github.com>

novelwriter/gui/mainmenu.py

@@ -993,6 +993,7 @@ class GuiMainMenu(QMenuBar):
         self.aPreferences.triggered.connect(self.mainGui.showPreferencesDialog)
         self.mainGui.addAction(self.aPreferences)
 
+    @pyqtSlot()
     def updateSpellCheckLanguages(self) -> None:
         """Update the list of available spell check languages."""
         self.mSelectLanguage.clear()