[Testing guide] Use "Fixtures API" instead of "fixture api".
[Testing guide] Using "Fixtures API" consistently

- In guides, "API" is used consistently instead of "api".
- Reason behind replacing "fixtures API" to "Fixtures API" is because
  here we are referring to the concept of "fixtures". In other places in
  the guide "fixture" OR "fixtures" is referred to the single or
  multiple instances of test data.
- This is also followup of https://github.com/rails/docrails/commit/aa9d1332b20305dd860b21a7ada06c5252bebad5#commitcomment-8497376.
Fix grammar on ActiveRecord::AttributeMethods doc.

[ci skip]
allow 'all' for :domain option in addition to :all
Don't remove mailer layouts files
Remove custom errors page section from the guides

This pattern is too problematic and introduces a lot of edge cases:

  * On 4.2, the issue https://github.com/rails/rails/issues/15124 is
    back again.
  * needs to define each action for each http status otherwise the
    router raises ActionController::RoutingError (No route matches).
  * If the router has `match "/*username",...` and some action is
    missing, Rails will pick up the "match" and try to do its job.
  * encourages people to copy & paste programming. Not DRY.

[ci skip]
Fix Sidekiq ActiveJob integration setup

* .connect on a Redis connection wasn't valid
* Reset logger after we're done testing for redis connection to avoid
  "closed stream" error when starting server for real from a fork
make OR in journey patterns compile to a valid regular expression
Hide potentially sensitive ActiveJob params from logs

* Show GlobalID instead of full object .inspect output
Merge branch 'master' of github.com:rails/rails
Fix value extracted from negative integers for PostgreSQL.

Fixes: https://github.com/rails/rails/issues/17856.
Merge pull request #17863 from tgxworld/fix_extracated_default_value_for_negative_integers

Fix value extracted from negative integers for PostgreSQL.
tests, use public API to verify default parsing. #17863, #17856
tests, run numeric default tests for every adapter.
Merge pull request #17827 from rkh/rkh-fix-or-pattern

Fix OR in Journey patterns
tests, favor public API over inspecting columns where possible.

This is a follow up to https://github.com/rails/rails/commit/07786c5e75a7b0afdf318063510af6b475e3e04c
and https://github.com/rails/rails/commit/cd2596f55e88fe659592612a793c4f4aa723c9be
Only filter GIDable objects; remove cosmetic changes
Bugfix config.action_view.default_form_builder option
Fix documentation for #default

Just a little syntax error I spotted by accident. Cannot pass hash with curly braces without normal parentheses.
Merge pull request #17869 from 2called-chaos/patch-1

Fix documentation for ActionMailer::Base#default [ci skip]