Use keyword arguments for ApplicationService calls

Not all services are using keywords, which breaks those calls in Ruby 3

app/controllers/signup_controller.rb

@@ -96,13 +96,13 @@ class SignupController < ApplicationController
     session[:new_user] = nil
     session[:validation_error] = nil
 
-    CreateAccount.call(
+    CreateAccount.call(account: {
       username: @user.cn,
       domain: Setting.primary_domain,
       email: @user.email,
       password: @user.password,
       invitation: @invitation
-    )
+    })
   end
 
   def set_context