HTML (all languages) appearing in error messages of multilingual sites

This was my quick fix. I don't know if the span needs to be there for some reason - it has no CSS in the Seven theme.

As previous patch, failed to apply.
Here is patch for 9.5.x

There will not be any 9.5 bug fix releases.

Patch for 11.x

This doesn't need tests, it's just a change and I'm not sure what we'd test for except that we changed it, however it does need the existing test coverage updated.

patch #7 works on my project with Drupal 10.3.9
<span class="translation-entity-all-languages">(all languages)</span> is now (all languages)