Add security/olm to FreeBSD Dockerfiles
This doesn't fix a broken build (yet), but there is a package not listed that is necessary to build libquotient in FreeBSD.
libquotient requires OlmConfig.cmake, which is provided by the security/olm package on FreeBSD.
I only found this while trying to build neochat using kdesrc-build, and olm wasn't brought in as a dependency on any packages I have installed locally. I decided to see what was listed in the Docker CI image, and see it's missing there as well. It must be brought in as a dependency by something else, but if that should change then this could become a problem. This just makes the requirement explicit.