Check when core .cspell.json changes and keep the assets files aligned

Problem/Motivation

Gitlab Templates has a deafult .cspell.json which is used for Contrib projects that do not have their own. It is based on the Core file (for some configuration items) but is intentionally not identical, due to the differing requirements of Contrib testing vs Core.

If/when the core file is updated, for example adding new flagwords, it would be beneficial if Gitlab Templates could also make these changes. This is a follow-up from 📌 Add blacklist and whitelist to flagWords Active

Proposed resolution

Add a step in our "Check Code" job to detect and alert of updates to the core file, or to check if specific configuration values no longer match the Gitlab Templates files.

Remaining tasks