fix: team user build use find or create by

app/models/team_user.rb

@@ -29,7 +29,7 @@ class TeamUser < ApplicationRecord
   before_destroy :remove_project_member
 
   def self.build(organization_id, user_id, team_id)
-    self.create!(organization_id: organization_id, user_id: user_id, team_id: team_id)
+    self.find_or_create_by!(organization_id: organization_id, user_id: user_id, team_id: team_id)
   end
 
   def remove_project_member