アイヌ語追加 (#428) (#433)

Reviewed-on: #433
Co-authored-by: miteruzo <miteruzo@naver.com>

backend/app/controllers/materials_controller.rb

@@ -255,7 +255,8 @@ class MaterialsController < ApplicationController
   end
 
   def resolve_material_tag! locale, tag_name_raw
-    Tag.find_or_create_by_tag_name!(locale, tag_name_raw, category: :material)
+    Tag.find_or_create_by_tag_name!(locale, tag_name_raw, category: :material,
+                                   created_by_user: current_user)
   end
 
   def material_index_needs_tag_name? filters