Documentation updates for Tails 4.0

This is meant to be a place to track things that were changed in Tails and need updates in the documentation.

• Traverso was removed (#16353 (closed))
• Scribus was removed

Subtasks

• #5323 (closed)
• #16284 (closed)
• #16753 (closed)

Related issues

• Blocks #16711

Original created by @Hefee on 16282 (Redmine)