tests/certs/generate: Generate X.509 version 3 CA. And pass CA:TRUE as basic constraint. This fixes the test suite with OpenSSL 3.2 with defaults to X.509v3 and CA:FALSE.
Avoid running randomized tests on the build daemons. These tests are racy and can fail in subtle ways depending on the machine load and speed. Basically `interimap --watch=1` is spawnedin the background, then random events (new messages, deletions, flag changes, etc.) are sent for for one minute, and the background process is later terminated and the mail stores compared. The problem is how to stop the background process after the loop. What's done right now is it waits for 5 seconds and sends a SIGTERM; unfortunately $n sec is arbitrary and might not be enough, depending on the machine and load. Ideally a SIGUSR1 would cause it to continue until a clean state is reached, then stop.
These tests most sense in the context of upstream development, so for now we skip them in the Debian context.
