Review deployment pipeline (response to 2022-05-25 staging crash)

[dunkOnIT]

From Gregor's reply in the email thread "Staging is down":

Never delete files simply because they are not tracked by git. In this case, an innocent "git clean" had the following collateral damage:

• Delete our entire secrets directory
  • Included SSH config which effectively locked us out for some time until Finn came to the rescue (thanks!!)
  • Included SSL certificates for browser website access
• Delete pre-cached content and daily calculated results data
• Delete all pre-compiled assets

[...] To be fair, this is a very strong argument in favor of redoing / rethinking our deployment process, but currently that's not our main focus. Instead, just make sure that you know what you're deleting.

We should try and review this process/put in place quick wins when we have capacity (I will try and get on this after Github projects and labels management)