Remove not working theme cache

(cherry picked from commit fc68d6fe)

aleksis/core/frontend/app/vuetify.js

@@ -40,10 +40,6 @@ const vuetifyOpts = {
   theme: {
     options: {
       customProperties: true,
-      themeCache: {
-        get: (key) => localStorage.getItem(key),
-        set: (key, value) => localStorage.setItem(key, value),
-      },
     },
   },
 };