i18n fallbacks test fixes

Reads much better doesn't it.

Stuff I see in passing while I am doing a walkthrough.

See rationale in 5b8738c2.

Stuff I see in passing while I am doing a walkthrough.

See rationale in 5b8738c2.

Stuff I see in passing while I am doing a walkthrough.

See rationale in 5b8738c2.

Stuff I see in passing while I am doing a walkthrough.

See rationale in 5b8738c2.

- Fixed test name for setting fallbacks to config.i18n.fallbacks = [{ :ca => :'es-ES' }]

Conflicts:
	guides/source/association_basics.md

[ci skip]

Fix typo `--ssl-cipher`

Follow up to #22543.

remove entry for reverted commit [ci skip]

Follow up to ddf4c953

chage `date_time` type ` to `datetime`

make attributes API  example to work [ci skip]

There is a need to pass the keyword arguments to `attribute` method.

Since we are using `datetime` in migration, better to use `datetime` is I think that confusion is less.

In the latest security releases render with a trailing slash no more call
render :file.

Also add a note about the security implications of using it with user
parameters.

Revert "Merge pull request #22764 from stevenspiel/titleize_model_name_for_default_submit_button_value"

This reverts commit 4158974c, reversing
changes made to 3d590add.

Reason: This break i18n in some languages. See
https://github.com/rails/rails/issues/791#issuecomment-192724640

remove config that are no longer needed in sprockets-rails 3

Remove http_cache_forever's version parameter

fix typo in attribute example [ci skip]

A small documentation fix about autosave associations [ci skip]

Defining paths relative to a file name has always hurt my soul,
with __dir__ we can restore order in the Universe.

`config.assets.raise_runtime_errors` and `config.assets.digest` are enabled
by default in sprockets-rails 3.

Fix indentation [ci skip]

remove outdated comment [ci skip]

Follow up to #24050.

Currently use minitest mock, mocha is not used.

Match Puma 3 startup messages [ci skip]

Introduce a predicate method that doesn't need to build a scope chain,
but also hides the data structure used for representing the scope chain.

Fix author callback in engines guide [ci skip]

https://github.com/rails/rails/pull/24052/files#r55083975

We know a reflection can be considered as `nested?` if the source
reflection or the through reflection are also through reflections (since
the through reflection will also add another join table).  This allows
us to avoid traversing the entire reflection tree just to calculate whether or
not there will be more join tables.

The `before_save` callback used with `set_author` results in the
validation error "Author must exist," due to the change in `belongs_to`
behavior introduced by #18937.

Use `before_validation` instead.