Wrong list of languages in placeholder text for live translations

[svenseeberg]

Describe the Bug

When mirroring another regions page with the live content function while the other region has different languages available, the resulting placeholder language list is wrong.

Example:

https://integreat.app/lkmuenchen/ru/%D1%80%D0%B0%D0%B1%D0%BE%D1%82%D0%B0-%D0%B8-%D0%BE%D0%B1%D1%83%D1%87%D0%B5%D0%BD%D0%B8%D0%B5/%D0%BF%D1%80%D0%BE%D1%84%D0%B5%D1%81%D1%81%D0%B8%D0%BE%D0%BD%D0%B0%D0%BB%D1%8C%D0%BD%D0%BE%D0%B5-%D0%BE%D0%B1%D1%80%D0%B0%D0%B7%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5/jibb-%D0%BC%D0%BE%D0%BB%D0%BE%D0%B4%D0%B5%D0%B6%D1%8C-%D0%B2-%D0%BE%D0%B1%D1%80%D0%B0%D0%B7%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B8-%D0%B8-%D1%82%D1%80%D1%83%D0%B4%D0%BE%D1%83%D1%81%D1%82%D1%80%D0%BE%D0%B9%D1%81%D1%82%D0%B2%D0%B5

Which uses a page of Munich as a source: https://integreat.app/muenchen/de/arbeit-ausbildung/unterst%C3%BCtzung-bei-der-suche-nach-einem-ausbildungsplatz/jibb-junge-menschen-in-bildung-und-beruf

Munich does not provide Russian translations but in general has more languages in its language tree. The number of items in the bullet point list seems to come from the live content source region, while the translations are then inserted based on the languages in the actual region.

Steps to Reproduce

1. Create 2 regions with some overlapping languages in the language tree
2. Create a page in the live content source region and fill all translations
3. Create a page with all translations in the other region
4. Set up live content from the second page to the first

Expected Behavior

The length list should only be based on the available languages in the region that is setting up the live content.

Actual Behavior

The length of the list is determined by the source region languages.

Additional Information

(https://chat.tuerantuer.org/digitalfabrik/threads/pf8xtob7ntnqipozwzp8cashkr

[osmers]

@svenseeberg could you give an estimate of the effort? Based on that I would possibly rank the priority higher....