Investigate possible dead code in \Drupal\ckeditor5\Plugin\CKEditor5Plugin\CodeBlock::parseLanguagesFromValue

Problem/Motivation

The method CodeBlock::parseLanguagesFromValue has the following return statement but $unparseable_lines is always empty.

return [$languages, $unparseable_lines];

This was discovered while working on 📌 Fix 12 'un' words RTBC

Steps to reproduce

Read https://git.drupalcode.org/project/drupal/-/blame/11.x/core/modules/cked...

Proposed resolution

TBD

Merge request link

Remaining tasks

Research the usage of parseLanguagesFromValue and the intention of $unparseable_lines

User interface changes

API changes

Data model changes

Release notes snippet