🔀🧑‍💻 auto-update GitHub issue with unmapped extendedCallList missions

[buffcode]

What kind of update does this PR provide? Please check

• new translations / updated translations / translation fixes
• a new feature
• a new module
• a bugfix for an existing feature / module
• improvement of style or user experience
• other: DX

Which language(s) did you add/update translations for?

• any language the extendedCallList module currently supports

What is included in your update?

• GitHub workflow that creates, updates (and closes) an issue for every event-mission, that isn't currently mapped inside the extendedCallList` module
• provides suggestions for grouping, based on the existing mapping
• preview: 🩹 [extendedCallList] Unmapped event missions buffcode/LSSM-V.4#3

Additional notes

• only missions with an end date in the future are considered, becase the list would be quite long otherwise. They will be added to the issue as soon as the game updates the mission data with a new date.
• Workflow runs every 6 hours (mission data is updated every hour according to @jxn-30), adjust to your liking.
• no token or secret required, runs as github-actions-bot if no token is configured

[jxn-30]

would it be possible to sort locales by alphabet? That would ease finding a locale.

Also I think I prefer the title 🩹 [extendedCallList] Unmapped event missions as title