We do not use double assign since 61f92f8b.

`def a() x = x = 1; end` warns since Ruby 2.5 (r59585)

Don't use remove_method or remove_possible_method just before a new
definition: at best the purpose is unclear, and at worst it creates a
race condition.

Instead, prefer redefine_method when practical, and
silence_redefinition_of_method otherwise.

Follow up of #30213

Add back a bit about a resource oriented style of routing.

- Auto-generating content from the filename of an image is not suitable
  alternative text; alt text that isn't fully considered can be
  distracting and fatiguing for screen readers users (blind, low vision,
  dyslexic people).
- Setting a filename fallback short circuits screen reader default
  behavior and configuration for blank descriptions.
- Setting poor defaults also creates false negatives for accessibility
  linting and testing software, that makes it harder to improve
  application accessibility.

***

- After this change, if authors leave images without alt text, screen
  readers will fallback to default behavior for missing alt text.
- Also with this change, Automated linting and testing tools will
  correctly generate warnings.

[Fixes #30096]

refs: https://github.com/rails/rails/pull/30161

```
$ echo "+@size+" | rdoc --pipe
<p>+@size+</p>

$ echo "<tt>@size</tt>" | rdoc --pipe
<p><code>@size</code></p>
```

[ci skip]

[ci skip]

The `@` ivar format doesn’t work with RDoc's `+` code formatting; needs `<tt>`.

[ci skip]

* Extend image_tag to accept ActiveStorage's Attachments and Variants

* Flip resolve_image_source around

* Add tests for the new use-cases of image_tag

* Remove the higher-level test

* Update image_tag documentation

* Add error states into the test suite

* Re-raise polymorhic_url's NoMethodError as ArgumentError

* delegate_missing_to will raise DelegationError instead of NoMethodError

FormHelper includes FormTagHelper so we don't need to define two methods

Also make sure file_field doesn't mutate the original options passed in.

When Active Storage is not loaded and direct_upload is used on
file_field_tag we should not raise an exception.

Explicitly pass a destructed array to the delegate method.
Signed-off-by: NYuki Nishijima <yk.nishijima@gmail.com>

Since methods defined in the controller helper are mostly delegated to
the controller, delegate respond_to? as well, so that for example
`respond_to?(:params)` behaves as expected.

This reverts commit 3420a145, reversing
changes made to afb66a5a.

Plus a couple of related ActionPack patches.

Includes two external changes because they're referenced within the ActiveModel test suite.

This makes sure that the labels are linked up with the fields.
Fixes #29014

That won't be true for Action Pack and Action Mailer.