This adds a script `bin/test` to most Rails framework components. The
script uses the rails minitest plugin to augment the runner.
See https://github.com/rails/rails/pull/19571 for details about the
plugin.

I did not yet add `bin/test` for activerecord, activejob and railties.
These components rely on specific setup performed in the rake-tasks.

This makes it possible to easily get the runner working with existing
setups that rely on `active_support/testing/autorun.rb`.

This reverts commit 3d949f34.

This was already documented in other PR.

Another use block variable instead of global

 Remove NOTE related to format.js [ci skip]

 - The example for which this NOTE was written was removed in
   https://github.com/rails/rails/pull/20493.

Removed AJAX example with poor convention adherence

The removed section promotes putting JS code directly inside the controller, this is not in line with convention.

Fix crash when loading fixture with belongs_to association defined in abstract base class

update Rails Command Line guide page

Fix typo in AM I18n validation test name

Use block variable instead of global

```ruby
Benchmark.ips do |x|
  x.report("$&") {
    "foo".gsub(/f/) { $&.hex }
  }
  x.report("block var") {
    "foo".gsub(/f/) { |match| match.hex }
  }
end
```

```
Calculating -------------------------------------
                  $&    23.271k i/100ms
           block var    24.804k i/100ms
-------------------------------------------------
                  $&    321.981k (± 7.4%) i/s -      1.606M
           block var    324.949k (± 9.2%) i/s -      1.612M
```

matches? should only deal with methods on the request object, so lets
just filter out anything that the request object doesn't respond to

this way we can remove the strange "respond_to?" conditional in the
`matches?` loop

add option to avoid generating scaffold.css

Raise an ArgumentError when `include_blank` is false for a required select field

`Tags::Base#select_content_tag`.

Previously, passing a falsey value to `include_blank` would be ignored if the
field was required, and a blank line would still be inserted. The following will
now raise instead of quietly failing:

`select("post", "category", %w(a required field), { include_blank: false }, required: 'required')`

[ci skip] Fix hours to minutes in `select_minute`

Add missing documentation for ActionDispatch::Request::Session [ci skip]

fix docs for Engines [ci skip]

Improve Test Runner's Minitest integration.

Fix core_text -> core_ext

[ci skip]

Code fix in CHANGELOG

:nail: remove extraneous bracket

Stop `to_s(:db)` for fixture's timestamp

add `instantiation.active_record` hook to instrumentation guide [ci skip]

Add missing NOTE for Time extensions' location

the hook was added in 2a0d97bc

Return a `Point` object from the PG Point type