While trying to fix #16433, we made the middleware deletions always
happen at the end. While this works for the case of deleting the
Rack::Runtime middleware, it makes operations like the following
misbehave.

```ruby
gem "bundler", "< 1.16"

begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"
  raise e
end

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  gem "rails", github: "rails/rails"
end

require "action_controller/railtie"

class TestApp < Rails::Application
  config.root = __dir__
  secrets.secret_key_base = "secret_key_base"

  config.logger = Logger.new($stdout)
  Rails.logger  = config.logger

  middleware.insert_after ActionDispatch::Session::CookieStore, ::Rails::Rack::Logger, config.log_tags
  middleware.delete ::Rails::Rack::Logger
end

require "minitest/autorun"
require "rack/test"

class BugTest < Minitest::Test
  include Rack::Test::Methods

  def test_returns_success
    get "/"
    assert last_response.ok?
  end

  private
    def app
      Rails.application
    end
end
```

In the case ☝️  the ::Rails::Rack::Logger would be deleted instead of
moved, because the order of middleware stack building execution will be:

```ruby
[:insert, ActionDispatch::Session::CookieStore, [::Rails::Rack::Logger]]
[:delete, ::Rails::Rack::Logger, [config.log_tags]]
```

This is pretty surprising and hard to reason about behaviour, unless you
go spelunking into the Rails configuration code.

I have a few solutions in mind and all of them have their drawbacks.

1. Introduce a `Rails::Configuration::MiddlewareStackProxy#delete!` that
delays the deleted operations. This will make `#delete` to be executed
in order. The drawback here is backwards incompatible behavior and a new
public method.

2. Just revert to the old operations. This won't allow people to delete
the `Rack::Runtime` middleware.

3. Legitimize the middleware moving with the new `#move_after` and
`#move_before` methods. This does not breaks any backwards
compatibility, but includes 2 new methods to the middleware stack.

I have implemented `3.` in this pull request.

Happy holidays! 🎄

Prevent NoMethodError on named route in integration test

Allow #nulls_first and #nulls_last in PostgreSQL

Add match 302 http code for log in redirect_to test

Update `open_ended?` to support new Ruby 2.6 endless and Ruby 2.7 beginless ranges

Fix collision check when using a generator and using the force option

Add ActiveRecord::Validations::NumericalityValidator

Add Active Record numericality validator with support for casting
floats using a database columns' precision value.

Only assign @new_record_before_save once in autosave_association

Use full option names in psql / pg_dump for clarity

If we defined a callback before an association that updates the object, then this may end up being
manipulated to being `false` when it should be `true`. We guard this be only defining it once.

The implication of it being false, in this case, is that the children aren't updated with the parent_id
and so they fail to associate to one another.

See https://github.com/rails/rails/issues/38120 for more details

Define mattr_* methods at caller's location

Avoid unnecessary SQL query when calling ActiveRecord::Relation#cache_key

Add `:round_mode` parameter support to number helpers

Fix the broken anchor of link [ci skip]

Support handling a `round_mode` in `ActiveSupport::NumberHelper::RoundingHelper`

Add default value to locale file

Update inline documentation with new parameter option

Update CHANGELOG

Add round_mode examples to all the tests

Add I18n test

Simplify logic

Further simpification

Include primary key in insert_all conflict target if specified

Before:

    [1] pry(main)> $ ActiveJob::Base.default_priority

    From: lib/active_support/core_ext/module/attribute_accessors.rb @ line 64:
    Owner: ActiveJob::QueuePriority::ClassMethods
    Visibility: public
    Number of lines: 3

    def #{sym}
      @@#{sym}
    end

After:

    [1] pry(main)> $ ActiveJob::Base.default_priority

    From: /home/jhawthorn/src/rails/activejob/lib/active_job/queue_priority.rb @ line 9:
    Owner: ActiveJob::QueuePriority::ClassMethods
    Visibility: public
    Number of lines: 1

    mattr_accessor :default_priority

Previously this was incorrectly defining this attribute on the singleton
class, which would end up actually using the class variable from Module.

https://buildkite.com/rails/rails/builds/66168#b348f446-0406-425e-ba53-c5d15034cf98/1002-1070

Fix adding non-null column to existing SQLite3 table

Forces adding the column by way of copying the table due to lack of
support in SQLite3 adapter.

Fixes #38129

Avoid assigning duplicate values to join_values

The ArgumentError occurs even though structures is compatible.
Because some query methods keep duplicate values.

For example, the behavior of `joins` method is as following:

```ruby
relation = Post.joins(:author).joins(:author)
relation.joins_values
#=> [:author, :author]
relation.or(Post.joins(:author))
#=> ArgumentError: Relation passed to #or must be structurally compatible. Incompatible values: [:joins]
```

This commit changes to not keep duplicate values.

Fixes #38052

Update "The Hard Way" setup for Arch Linux

MariaDB cannot be started on Arch Linux before running a command to create the database files

See https://wiki.archlinux.org/index.php/MariaDB#Installation

It also appears that memcached is not started by default on Arch Linux,
so it has been added to the systemctl startup step.

This PR adds that step when setting up on Arch Linux

Pass env_name as a string in test databases

In 154abcab we switched from using `Rails.env` to fetch the `env_name` to
`ActiveRecord::ConnectionHandling::DEFAULT_ENV.call.to_sym` which
changed the type from a `String` to a `Symbol`.

This commit brings things back to the original state, so we can find the
configurations correctly!

It also modifies the configuration in the configurations array, so that
future connections can find the database with the updated keyword value.

When all IPs are trusted, use the furthest away