Merge pull request rails#53154 from byroot/unpin-unowned-connections

ConnectionPool#unpin_connection! handle lazily pinned connections

Author: byroot

activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb

@@ -357,6 +357,7 @@ def unpin_connection! # :nodoc:
           end
 
           if @pinned_connection.nil?
+            connection.steal!
             connection.lock_thread = nil
             checkin(connection)
           end