Add locales to the image

[SchoolGuy]

Atm my TYPO3 installation is throwing a lot of the following errors:

Thu, 09 May 2024 12:54:55 +0000 [ERROR] request="17945dc0d5348" component="TYPO3.CMS.Core.Localization.Locales": Locale "de_DE.UTF-8" and  "de_DE" not found. 

This is due to the reason that the locales package is not installed and the corresponding config is not enabled for German. Would you accept a PR that adds this to the image?

If desired by you I would be willing to contribute a startup script that runs the locale generation based on an environment variable.