ci: Remove OpenSSL 3.1 workaround for missing system CA
Commit
0b5d1fb36 fixed the SSL test to properly handle the error message
from OpenSSL when the system CA pool is missing of invalid, so with that
we can remove the workaround in Cirrus for when Homebrew clears the cert
from OPENSSLDIR.
Author: Jacob Champion <jchampion@timescale.com>
Discussion: https://postgr.es/m/CAAWbhmj3JtKuRcHcMuf1eCJmoZxMXdzLaYpEGmzu9+kgRGpu3A@mail.gmail.com