Translation files are not compiled for docker images latest/latest-dev

[hbruch]

When starting superset using docker-compose-non-dev.yml, many messages are rendered untranslated, though the .po files include translations for their keys.

How to reproduce the bug

1. Enable a rather complete language in superset_config_docker.py:

BABEL_DEFAULT_LOCALE = "de"
LANGUAGES = {
    "de": {"flag": "de", "name": "Deutsch"},
    "en": {"flag": "us", "name": "English"},
}

2. Start superset via docker-compose -f docker-compose-non-dev.yml' p -d
3. Open http://localhost:8088/
4. See a couple of untranslated messages

Expected results

See messages translated in .po files to appear translated in the frontend

Actual results

Messages translated in .po files appear untranslated in the frontend

Checklist

Make sure to follow these steps before submitting your issue - thank you!

• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven't found one similar. (relates partly to Translations files don't translate everything #14848)

Additional context