* Add test for the new exception of delegate_missing_to

* Add a changelog entry

* Only check for nil if NoMethodError was raised

* Make method private

* Have to pass both target name and value

* Inline the re-raise

[Rafael Mendonça França + Anton Khamets]

This comment was added at 97849deb, but `AssociationProxy` and
`test_triple_equality` was removed at 1644663b. Currently the `===` is
used for `test_decorated_polymorphic_where` that added at #11945.
So I updated "association proxies" to "decorated models".

And also, currently `Core::ClassMethods` appears in the doc.

http://api.rubyonrails.org/classes/ActiveRecord/Core/ClassMethods.html

But it looks like that the methods in the module is not public API.
So I also added `# :nodoc:` to the module.

Optimize indentation for generator actions

Add code formatting and minor grammar clarifications

Fixed query building when relation is passed for has one or has many association in where 

Eager load controller actions to reduce response time of the first request

Removed empty line from dummy_manifest

Add `:authors` to address random failures at HasOneAssociationsTest

Merge pull request #30116 from yhirano55/skip_unused_components_when_running_rails_command_in_plugin

Skip unused components when running `bin/rails` in Rails plugin

Remove :sorted test order for isolated tests

Activestorage rack test uploaded file

Add git_source to Gemfile for plugin generator

Improve callback examples in Active Job guide

Use copy to preserve file permissions

Prevent generation extra empty lines in a plugin's Rakefile

[Active Storage] `rubocop -a --only Layout/TrailingBlankLines`

ActiveStorage: Remove unnecessary require in test_helper

Active Storage was now merged to master and it is automatically
installed in a new application.

Return Not found Ids in ActiveRecord::NotFound

More robust PostgreSQL database duplication check

Evaluate `@active_storage_attached_#{name}` only once

Add `null: false` to Active Storage tables

Fixes #29045.

These columns aren't intended nullable.

Currently `"@active_storage_attached_#{name}"` in `define_method` is
evaluated every call. It is better to evaluate it only once.

Fix generator example code [ci skip]

Fix RDoc formatting: `+` doesn't work with `@` [ci skip]

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] Update testing.md [ci skip] 

Fix formatting of Active Storage docs [ci skip]

Follow up of #30188.