Mitigate BPF security issues on our infrastructure

Originally created by @intrigeri on #15094 (Redmine)

https://www.decadent.org.uk/ben/blog/bpf-security-issues-in-debian.html

Seems important (at least LPE and probably remotely exploitable given Ben blogged about it; public exploit is in the wild) and super cheap to implement now (and waiting won’t make it any cheaper).

Feature Branch: puppet-tails

Related issues

• Related to tails/tails#15095