library_info_alter can abort early if locale is not enabled

Problem/Motivation

This is in ckeditor5_library_info_alter, not inside any conditionals:

// Only add translation processing if the locale module is enabled.
  if (!$moduleHandler->moduleExists('locale')) {
    return;
  }

So if locale isn't enabled, the alter aborts early.

This was discovered while working on #3194084: Support functionality equivalent to ckeditor_stylesheets, as it prevented the solution from working.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet