This proposal is based on a [code review comment][]:

> I think we should deprecate and remove this module. It is only used
> once inside the framework, in a place that perhaps don't even need it
> anymore and I don't think it adds much for our users. They would be
> better served with their own config object that is just a hash.

To achieve this outcome, replace the only internal occurrence of
`ActiveSupport::Configurable` with a [class_attribute][]. Similarly,
replace [config_accessor][] calls with class- and instance-level calls
to [delegate][] for the readers and writers.

[code review comment]: https://github.com/rails/rails/pull/53796#issuecomment-2512417545
[class_attribute]: https://edgeapi.rubyonrails.org/classes/Class.html#method-i-class_attribute
[config_accessor]: https://edgeapi.rubyonrails.org/classes/ActiveSupport/Configurable/ClassMethods.html#method-i-config_accessor
[delegate]: https://edgeapi.rubyonrails.org/classes/Module.html#method-i-delegate