Increase sleep time to fix flaky test

InnoDB seems to raise the error "Lock wait timeout exceeded"
more than innodb_lock_wait_timeout seconds.

spec/activerecord/debug_errors/ext/connection_adapters/abstract_mysql_adapter_spec.rb

@@ -74,10 +74,11 @@ def cause_deadlock(role:)
 
         ths = Array.new(2) do
           Thread.new do
+            Thread.current.abort_on_exception = true
             User.transaction do
               barrier.await(1)
               User.lock.find_by!(name: 'foo')
-              sleep 2
+              sleep 5
             end
           end
         end