Update update_responses_config.yml to allow 11.5.8 to update to whatever latest is

So as a stop-gap to get 12.0 out, we added a set of RewriteRules to the update_pre12.0 .htaccess which redirects users to a locally copied set of 12.0 XMLs. With the current rules in place, users will need update from pre-11.5.8 -> 11.5.8 -> 12.0 -> latest. We need to update the generated .htaccess rules to migrate 11.5.8 to latest.

We should also remove the stop-gap rules in update_pre12.0 on staticiforme once the script to generate the .htaccess is updated.