Fix "openssl/rand.h" OSX tests
I tried to add CPPFLAGS to the OSX CI job, but that didn't work neither, see https://0xacab.org/varac/bitmask-dev/builds/10775
I tried to add CPPFLAGS to the OSX CI job, but that didn't work neither, see https://0xacab.org/varac/bitmask-dev/builds/10775