Use SHA-1 for non-sensitive digests by default

Fix doc typo [ci-skip]

Fix some broken links in guides

Closes #31273 but we will still want to upgrade this to the
nonce-approach when it’s ready.

Fix typos, update documentation

[ci skip]

This will avoid the branch being deleted by mistake making all builds to
fail.

PostgreSQL: Allow pg-1.0 gem to be used with ActiveRecord

Fix typos [ci skip]

add instrumentation for read_multi

Add support for Minitest 5.11

When deleting through records, take into account association conditions

This option was moved into active_record_deprecated_finders in ac4d101a.

Queue_classic currently limits pg to "< 0.20".
It is therefore not used for rails CI tests. There has been
a bull request for a while (by a co-worker of mine), which
fixes the incompatibilities and extends dependencies to pg-1.x.

This patch add this pull request to the Gemfile as an interim
solution, until it is merged.

pg-1.0.0 is just released and most Gemfiles don't restrict
it's version. But the version is checked when connecting to
the database, which leads to the following error:

Gem::LoadError: can't activate pg (~> 0.18), already activated pg-1.0.0

See also this pg issue:
https://bitbucket.org/ged/ruby-pg/issues/270/pg-100-x64-mingw32-rails-server-not-start

Preparation for pg-1.0 was done in commit f28a3310,
but the pg version constraint was not yet relaxed.

`find_with_associations` is meaningless name in this point since it just
contain `construct_join_dependency` and `apply_join_dependency`, does
not contain finding anything.
If `apply_join_dependency` returns `relation` and `join_dependency` then
`find_with_associations` is no longer needed.

`relation.exists?` just wants to know if there is a result or not, does
not need the exact records matched. Therefore, an intermediate SELECT
query for eager loading is not necessary.

Fix :inverse_of documentation

[ci skip] setting :inverse_of works with :as, :through and :polymorphic options, and is needed for bi-directionality with a scope

[ci skip] Remove :conditions opion from association basics guide

This got replaced by scopes.

Need reloading when through record has replaced.

Clean up railties tests

Merge pull request #16314 from zoltankiss/allow-nested-has-many-associations-on-unpersisted-parent-instances

fix nested `has many :through` associations on unpersisted parent instances

  Remove `AppGeneratorTest#test_active_storage_install`.
  The test is added by 67db41aa,
  since #31534 this test doesn't test anything.

  Remove redundant assertions in `SharedGeneratorTests`.
  These assertions is added by 4a835aa3.
  Follows 67db41aa, #31534.

I removed redundant `Array.wrap(records)` since `Preloader` is nodoc
class and Active Record always pass `records` as an array to
`Preloader`.
But if users relies on that behavior, it is not worth dropping its
behavior.

Fixes #31661.

Fix performance issue with NameError#missing_name on ruby >= v2.3.0.

Consistency between first() and last() with limit

Don't include Active Storage migrations in new apps