In Rails 6.1, the classic autoloader is deprecated.
We were getting an error because we were using `autoload` in the
ActiveStorage plugin for CKEditor:
expected file app/lib/ckeditor/backend/active_storage.rb to define
constant Ckeditor::Backend::ActiveStorage
So we're removing the line causing the error.
Finally, we can now restore all the tests that that failed sometimes
with the classic autoloader and that we modified in commits 2af1fc72f
and 8ba37b295.
The purpose of the lib folder is to have code that doesn't necessary
belong in the application but can be shared with other applications.
However, we don't have other applications and, if we did, the way to
share code between them would be using a gem or even a git submodule.
So having both the `app/` and the `lib/` folders is confusing IMHO, and
it causes unnecessary problems with autoloading.
So we're moving the `lib/` folder to `app/lib/`. Originally, some of
these files were in the `app/services/` folder and then they were moved
to the `lib/` folder. We're using `app/lib/` instead of `app/services/`
so the upgrade is less confusing.
There's an exception, though. The `OmniAuth::Strategies::Wordpress`
class needs to be available in the Devise initializer. Since this is an
initializer and trying to autoload a class here will be problematic when
switching to Zeitwerk, we'll keep the `require` clause on top of the
Devise initializer in order to load the file and so it will be loaded
even if it isn't in the autoload paths anymore.
