Upgrade server hardware (2017-2019 edition)

Originally created by @Dr_Whax on #11680 (Redmine)

This includes:

• storage: update the spreadsheet we did for tails/sysadmin#10851 and draw conclusions wrt. how much more storage we need to add
• reproducible builds’ needs
• running the test suite on bare metal?
• asking server hardware sponsorship or discount to hardware vendors?
• using the cloud?

Blueprint: https://tails.boum.org/blueprint/hardware_for_automated_tests_take3/

Subtasks

• tails/sysadmin#11806
• tails/sysadmin#13425
• #15501 (closed)
• tails/sysadmin#15780

Related issues

• Related to tails/sysadmin#10851
• Related to tails/tails#14601
• Related to tails/sysadmin#16960