Update translation CI to account for the extended 13.5 release

If we're maintaining the 13.5 build, we will need to keep these strings around as well.

Currently the translation CI combines the strings in:

1. the default (development) branch, with
2. the branch with the latest tor-browser-*-build1 tag with the word "stable" in the annotations. E.g. the tor-browser-115.15.0esr-13.5-1-build1 with the annotation "Tagging build1 for 115.15.0esr-based stable".

@pierov @morgan how will I be able to identify the latest extended 13.5 branch? How will the name the branch, or tag it for building?

Also, will the logic of searching for the "stable" tag still work to identify the stable 14.0 release branch? Or will the extended 13.5 branch also include "stable" tags?