[11.x] Modify doc blocks for getGateArguments

[saMahmoudzadeh]

This PR, fixes @return for getGateArguments method in Authorize.php

// Before
 /**
   * Get the arguments parameter for the gate.
   *
   * @param  \Illuminate\Http\Request  $request
   * @param  array|null  $models
   * @return \Illuminate\Database\Eloquent\Model|array|string
   */
  protected function getGateArguments($request, $models)
  {
      if (is_null($models)) {
          return [];
      }

      return collect($models)->map(function ($model) use ($request) {
          return $model instanceof Model ? $model : $this->getModel($request, $model);
      })->all();
  }

If $models is null in the getGateArguments method, an empty array is returned; otherwise, an array is still returned because the all() method in collections returns an array.

/**
   * Get all of the items in the collection.
   *
   * @return array<TKey, TValue>
   */
  public function all()
  {
      return $this->items;
  }

In the all() method, $this->items is always an array. Therefore, we can change the @return for the getGateArguments method to an array.

// After
 /**
   * Get the arguments parameter for the gate.
   *
   * @param  \Illuminate\Http\Request  $request
   * @param  array|null  $models
   * @return array
   */