Remove `all_components.js` and `all_components.scss`

[MartinJJones]

What

Remove all_components.js and all_components.scss

Why

To avoid excessive code from being imported in the application.

Both all_components.js and all_components.scss files are marked as "(deprecated, will be removed in a later version)" in the install and use docs.

Further info

• all_components.js marked as deprecated - https://github.com/alphagov/govuk_publishing_components/pull/1472
• all_components.scss marked as deprecated - https://github.com/alphagov/govuk_publishing_components/pull/1321
• RFC108 - Include specific component assets in applications