Add Rails 7.1 edge support

[tagliala]

  undefined method `direct_descendants' for class `#<Class:Bar(id: integer, name: string, foo_id: integer)>'

Bisected to rails/rails@1aa2463 rails/rails#46144

ActiveSupport::DescendantsTracker.direct_descendants is deprecated and will be removed in Rails 7.1.
Use ActiveSupport::DescendantsTracker.subclasses instead.

[tagliala]

Another breaking change:

rails/rails@57bc28f rails/rails#44576

[tagliala]

Subclasses is not an alias of direct_descendants until rails/rails@8f8aa85 rails/rails#39505

[tagliala]

subclasses doesn't work with Ruby 3.1 stable

[tagliala]

Another breaking change

  1) rails dbconsole rails dbconsole is expected to be successfully executed
     Failure/Error: specify { expect(last_command).to be_successfully_executed }

       Expected `bash -c "echo 'select 1 as foo_column; \q' | bundle exec rails db"` to succeed but got non-zero exit status and the following output:

       Unknown command-line client for chronomodel_railsapp.

  2) rails dbconsole rails dbconsole is expected to have output: /\bfoo_column\b/
     Failure/Error: specify { expect(last_command).to have_output(/\bfoo_column\b/) }

[tagliala]

dbconsole change:

rails/rails@4bcb8e4 rails/rails#46093