Remove deprecated calls to routing mapper

[etiennebarrie]

See rails/rails#52422

[stevenharman]

Thanks for the contribution, @etiennebarrie. If I'm following the linked PRs correctly, this deprecation won't take place until Rails 8.0. And the keyword based API (using to: and at:) has been supported for… a long time! Meaning our existing dependency constraints on railties >= 6.1 should be fine.

If all of that is correct, this is 👍 for me.

[etiennebarrie]

Oh sorry I forgot to add some details. Yes this is what I found as well, to:, at: have been here for a long time, no risk on backwards compatibility. 👍

Yes Rails 8.0 will deprecate this syntax. Some of us run Rails main in production 😇