Prepare changes for 7.0.0

Fix rails 8 build with 2781 and 2783

rails_helper template: Restore old order of support files

Before #2678, the suggested code snippet for loading support files loaded files in directories (e.g. `spec/support/a/b.rb`) *after* files with the same basename as those directories (e.g. `spec/support/a.rb`).

This tends to be the preferrable load order, given how Ruby modules and classes are usually structured.

The root cause is a difference between the alphabetic ordering of string sorting compared to `Pathname#<=>`.

Rails main requires `sqlite3` version 2:
https://github.com/rails/rails/pull/51958

Rails `main` uses Thor for the `bin/rails stats` command instead of
Rake. This means stats directories need to be added in the Railtie.

The global constant STATS_DIRECTORIES defined by Rails, has been
deprecated in favor of Rails::CodeStatistics.register_directory.

https://github.com/rails/rails/blob/8c7754dfdf39ed94cc93bbc40ee721c311b6d32c/railties/CHANGELOG.md?plain=1#L1-L11

Refactor active job matcher

Previous PR had split this up to avoid a rubocop rule infringment but
did so in a way making it less clear what happened, we could turn off
the rule instead for this method but refactoring the job matching method
also satisfies the rule without sacrificing readability.

Move conditional `cell_selector` out of generated view spec

Co-authored-by: Phil Pirozhkov <hello@fili.pp.ru>

Add Rails 7.2 to CI matrix

This causes a file generation conflict in Rails 7.2, as they seem to
already exist. We don't want to overwrite whatever there is.

```
    conflict    app/assets/config/manifest.js
  Overwrite /Users/pirj/source/rspec-dev/repos/rspec-rails/tmp/example_app/app/assets/config/mani
  Overwrite /Users/pirj/source/rspec-dev/repos/rspec-rails/tmp/example_app/app/assets/config/manifest.js? (enter "h" for help) [Ynaqdhm] y
       force    app/assets/config/manifest.js
    conflict    app/assets/stylesheets/application.css
  Overwrite /Users/pirj/source/rspec-dev/repos/rspec-rails/tmp/example_app/app/assets/stylesheets
  Overwrite /Users/pirj/source/rspec-dev/repos/rspec-rails/tmp/example_app/app/assets/stylesheets/application.css? (enter "h" for help) [Ynaqdhm] y
       force    app/assets/stylesheets/application.css
```

Support `have_http_status` with `Rack::MockResponse`

docs: Use `perform_enqueued_jobs` in an example code

`perform_jobs` should be `perform_enqueued_jobs`,
so I fix the example codes.

ref. https://guides.rubyonrails.org/testing.html#testing-jobs-in-isolation