fix department show deleted

app/controllers/departments_controller.rb

@@ -1,6 +1,6 @@
 class DepartmentsController < ApplicationController
   def for_option
-    render_ok(departments: current_school.departments.select(:id, :name).as_json)
+    render_ok(departments: current_school.departments.without_deleted.select(:id, :name).as_json)
   end
 
   private

app/models/department.rb

@@ -2,4 +2,6 @@ class Department < ApplicationRecord
   belongs_to :school
 
   has_many :department_members, dependent: :destroy
+
+  scope :without_deleted, -> { where(is_delete: false) }
 end