Explicit route test class

shows the class that the test must extend in order to have the assert_routing method available
FileHandler should not be called for files outside the root

FileHandler#matches? should return false for files that are outside the
"root" path.
AR::UnknownAttributeError should include the class name of a record

This would be helpful if 2 models have an attribute that has a similar
name to the other. e.g:

before:

    User.new(name: "Yuki Nishijima", projects_attributes: [name: "kaminari"])
    # => ActiveRecord::UnknownAttributeError: unknown attribute: name

after:

    User.new(name: "Yuki Nishijima", projects_attributes: [name: "kaminari"])
    # => ActiveRecord::UnknownAttributeError: unknown attribute on User: name
Use include_blank value as option label

Update select_tag to reflect documentation and behave the same as form builder select. If the value of include_blank is not boolean true, use that value as the option label.
[ci skip] A Rails engine is not a man :ok_woman:
[ci skip] add :queue option to deliver_later and deliver_later! documentation
Merge pull request #17314 from y-yagi/message_delivery_doc

[ci skip] add :queue option to deliver_later and deliver_later! documentation
:nail_care: it's -> its (see comments on 9a586ac)
make guides example more friendly to nonlatin langs
Merge pull request #17318 from igas/guides-more-friendly-for-nonlatin

make guides example more friendly to nonlatin langs [ci skip]
fix wrong #17318 [ci skip]
Merge pull request #17319 from igas/fix-17318

fix wrong example from #17318 [ci skip]
Make _status_code methods nodoc

- Also one minor change for documenting url_for method in ActionController::Metal.
[ci skip]
Merge pull request #17321 from prathamesh-sonpatki/nodoc-status_at

Make status_at methods nodoc
Fixed test throwing unused variable warning
Merge pull request #17322 from vipulnsward/fix-test-warning

Fixed test throwing unused variable warning
Enable emitting of warnings from ActiveJob tests.
- Removed unused variable warnings from ActiveJob Adapters
remove duplicate method (_status_code) in action_dispatch
Merge pull request #17323 from seuros/master

remove duplicate method (_status_code) in action_dispatch