Discourse was updated due to T294529: CVE-2021-41163 and discourse-mediawiki.wmflabs.org, which broke login:
ArgumentError (wrong number of arguments (given 2, expected 1)) lib/user_name_suggester.rb:7:in `suggest' app/controllers/users/omniauth_callbacks_controller.rb:35:in `complete' app/controllers/application_controller.rb:408:in `block in with_resolved_locale' app/controllers/application_controller.rb:408:in `with_resolved_locale' lib/middleware/omniauth_bypass_middleware.rb:50:in `call' lib/content_security_policy/middleware.rb:12:in `call' lib/middleware/anonymous_cache.rb:354:in `call' config/initializers/100-quiet_logger.rb:23:in `call' config/initializers/100-silence_logger.rb:31:in `call' lib/middleware/enforce_hostname.rb:23:in `call' lib/middleware/request_tracker.rb:198:in `call'