use native Notification table and migration

app/Models/User.php

@@ -57,16 +57,4 @@ class User extends Authenticatable
     public function tasks() {
         return $this->belongsToMany(Task::class);
     }
-
-    public function notifications(): \Illuminate\Database\Eloquent\Relations\BelongsToMany
-    {
-        return $this->belongsToMany(
-            Notification::class,
-            'notification_user',
-            'user_id',
-            'notification_id',
-        )
-            ->withPivot('unread')
-            ->withTimestamps();
-    }
 }