ActiveModel::Errors

Fixes #16518

move cache_digests rake methods into their own namespace

Don't use shorthand match on routes with inappropriate symbols

These methods are nodoc so we should not document them.

Isolate access to @associations_cache and @aggregations_cache to the Associations and Aggregations modules, respectively.

Move the `validate!` method to `ActiveModel::Validations`.

Simplify find_by_statement_cache interaction

Active Job Guide: Use sentence case for consistency in comments [ci skip]

[ci skip]

Fix cache_helper comment ERB typo

Always reset changed attributes in becomes

mail_to helper method fix

Format the time string according to the precision of the time column

Allow `method: "all"` as a valid routing test option

fix mistype in doc about \z regexp

Rename default_form_builder to avoid collision

Corrects the API to method select_tag

use `messages` instead of deprecated `ActiveModel::Errors#[]=` method [ci skip]

The 'selected' option is not doing what it should do.
The expected behavior is to pass the value selected by default for the options_from_collection_for_select method

It is also necessary to format a time column like a datetime column.

Cache url_helpers instead of creating each time

This has 2 effects:

1. RoutesProxy is CRAZY faster because it's no longer creating a new
Module each time method_missing is hit.
2. It bypasses an existing bug in ruby that makes `class << obj` unsafe
to be used in threading contexts.

Remove last empty line when we don't use Windows or JRuby

fix column name in migration example [ci skip]