Fixes an issue where time_zone_conversion that causes an exception in…

Following off of https://github.com/rails/rails/issues/15945, I realized that super
needs to be the first thing that is called in an AbstractModel's inherited method.
I was receiving errors within the inherited method of time_zone_conversion, so I tested
locally by moving super to the top of the method declaration. All exceptions went away.

Use Regexp#match? rather than Regexp#===

Regexp#match? should be considered to be part of the Ruby core library. We are
emulating it for < 2.4, but not having to require the extension is part of the
illusion of the emulation.

remove unused `RedirectBackError` class

Follow up to 333bfd89

fix initializer name [ci skip]

This changed in c0466603

This executor currently relies on `ActiveRecord::Base.connection` not
changing between `prepare` and `complete`. If something else returns
the current ActiveRecord connection to the pool early then this
`complete` call will fail to clear the correct query cache and restore
the original `query_cache_enabled` status.

This has for example been happening in Sidekiq:

     https://github.com/mperham/sidekiq/pull/3166

We can just keep track of the connection as part of the exector state.

There were never public API only there by mistake.

[ci skip]

Follow up to 99cf7558.

Update HABTM documentation in guides [ci skip]

Ensure `#transform_values` of HWIDA to return HWIDA

On Ruby 2.4, naitive `Hash#transform_values` is implemented.
`Hash#transform_values` uses an instance of Hash (`rb_hash_new`) to
collect returned values of a block.
For ensuring `#transform_values` of HWIDA to return HWIDA, we should
define `#transform_values` on HWIDA.

Merge pull request #25432 from kamipo/polymorphic_reflection_is_not_using_methods_from_through_reflection

`PolymorphicReflection` is not using the methods from `ThroughReflection`

update kindlerb gem

This image has copyright that we are not giving so it is better to use
one image that we own the copyright.

render :html escapes the argument if not provided as html safe.

Fix small typo in ActionView API documentation [ci skip]

Fix brittle tests which were relying on the error message text from mysql2 gem

Uses queue adapter_method instead of ActiveJob::Base.queue_adapter

Change ActiveJob::Base.queue_adapter to use queue_adapter method to make test code consistent.

Use Hash#compact and Hash#compact! from Ruby 2.4

remove assets config from `new_framework_defaults` if `--skip-sprockets` is true

If `sprockets` is not loaded, `Rails.application.config.assets` is not defined.

* Put a blank line after :call-seq: otherwise it will think the whole test
is the call seq.
* Improve some text.
* Use some rdoc formatting.
* Restores the documentation of table_name_prefix.

[ci skip]

Fix model schema doc strings

Fix typo in Upgrading Ruby on Rails Guide [ci skip]

update description of Etag [ci skip]

The document is written with "only generate weak", but it can also be used to
strong etag.
Also, add missing entory for #24387