data: Mark release descriptions as untranslatable

[ghost]

GNOME automatically excludes release descriptions on Damned Lies (GNOME Translation Platform). It's a good practice to follow the GNOME way.

This can streamline the translation process, allowing translators to focus their efforts on more critical and user-facing aspects of the application.

Also:

• Update the POT file
• Update Turkish translation

[tfuxu]

Thanks 👍️