Add use_turbo configuration with default to false.

[gobijan]

This PR enables Rails 7 and Devise to work out of the box.
Devise now opts out of turbo by default for its forms by making use of
data: { turbo: Devise.use_turbo} setting on forms.

I've seen this PR #5487 but it is not configurable and hardcoded. So people that have opted into turbo can do this via a setting (maybe they fixed notifications by patching devise etc.).
I went with an approach that conforms to the style I've seen by inspecting the devise codebase.

My PR defaults to not using turbo in devise forms by default. I know this is a minor breaking change for people that might have patched the problem otherwise but it's the way to offer a sane default experience with Devise and Rails 7 until the maintainers decide on a real solution.

[msducheminjr]

On the registrations/edit view, it is also necessary to handle the confirm on Cancel my account so that a user doesn't accidentally misclick and bypass the confirmation in Turbo.

Something like this:

<% confirm_attribs = devise_mapping.use_turbo ? { form: { data: { turbo_confirm: "Are you sure?" } } } : { data: { confirm: "Are you sure?" } } %>
<p>Unhappy? <%= button_to "Cancel my account", registration_path(resource_name), **confirm_attribs, method: :delete %>

[carlosantoniodasilva]

The main branch should contain all that's necessary for fully working with Turbo now, based on the changes here and a few others. A new version will be released soon, but feel free to test it out from the main branch in the meantime, and report back on any issues. Thanks.