Use `FORTIFY_SOURCE=3` somewhere on CI
Since glibc 2.34 and GCC 12, there is a new FORTIFY_SOURCE level (3) that would be nice to have on CI.
You can read more about it here for example:
https://developers.redhat.com/articles/2022/09/17/gccs-new-fortification-level#
@ben.boeckel is there a bot with new enough glibc / gcc that this could be added to?
(See also #18100.)