Update docs for Tails 4

[eloquence]

We want to

• review all references in the documentation for accuracy against Tails 4/SecureDrop 1.1.0
• prioritize and update the highest priority issues (e.g., incorrect instructions or screenshots that are confusing) for 1.1.0.

This includes but is not limited to Tails references in the following sections:

• Journalist Guide - a lot of very specific Tails guidance here, e.g., regarding use of VeraCrypt
• Printer setup docs
• Install docs ("Additional software" prompt)
• SVS setup docs
• Submission Key generation
• Network firewall setup (e.g., "unsafe browser" use, network config on the AWS)

We should also sanity check:

• Backup docs
• Update docs
• YubiKey docs

[rocodes]

Working on this today.

[eloquence]

#4937 updates the printer and SVS docs, and I've verified that the VeraCrypt docs still work. #4942 at least partially updates several other docs, including the Submission Key generation, the network firewall instructions, and the journalist guide. @rocodes, can you confirm if any additional work or due diligence remains to be done on the following?

Submission Key generation
Network firewall setup (e.g., "unsafe browser" use, network config on the Admin Workstation)
Backup docs
Update docs
YubiKey docs

[rocodes]

Submission key generation: I have screenshots with (slightly) updated UI, although current docs are not incorrect. Yubikey and Update docs I'd still like to review.

I can update tomorrow.