fix(translation): include babel-compile in Dockerfile (#17876)

[hbruch]

SUMMARY

Adds babel-compile step in Dockerfile.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

After:

TESTING INSTRUCTIONS

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. build docker images via docker build -t apache/superset:latest-dev .
3. Start superset via docker-compose -f docker-compose-non-dev.yml' up -d
4. Open http://localhost:8088/
5. See formerly untranslated messages now translated

ADDITIONAL INFORMATION

• Has associated issue: Fixes Translation files are not compiled for docker images latest/latest-dev  #17876
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[hbruch]

@villebro Seems like there was a temporay problem with git checkout (?) Could you restart the checks (or could I do this myself?)

[villebro]

LGTM!