Update with Rails 7 and 7.1

[gregmolnar]

@presidentbeef Rails 7 and 7.1 and current main has the same list of dangerous methods as 6 and I wonder if you would be open to a pull request changing Rails 6 to Rails 6+ or Rails 6 onwards.
Alternatively the same page could be copied to Rails 7.

[gregmolnar]

Since there are links to the docs, a new page would make more sense for Rails 7. If you are open to it, I would be happy to open a pull request for that.