[CHANGE] Update FA icons to new classes

Base Classes:
- `far` => `fa-regular`
- `fas` => `fa-solid`
- `fab` => `fa-brand`

allianceauth/menu/models.py

@@ -144,7 +144,7 @@ class MenuItem(models.Model):
                     "render": _render,
                     "text": mi.text,
                     "rank": mi.rank,
-                    "classes": (mi.icon_classes if mi.icon_classes != "" else "fas fa-folder"),
+                    "classes": (mi.icon_classes if mi.icon_classes != "" else "fa-solid fa-folder"),
                     "hide": mi.hide
                 }