chore: raise a specific error

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

app/controllers/oauth_callback_controller.rb

@@ -82,7 +82,7 @@ class OauthCallbackController < ApplicationController
   end
 
   def account_from_signed_id
-    raise 'Missing state variable' if params[:state].blank?
+    raise ActionController::BadRequest, 'Missing state variable' if params[:state].blank?
 
     GlobalID::Locator.locate_signed(params[:state])
   end