[PKGS-7398] NixOS: Add package audit tool vulnix

[felbinger]

Is your feature request related to a problem? Please describe.
When running lynis audit system on nixos no package audit tool is recognized, even though vulnix is installed. I think vulnix is this kind of package (just like zypper or pkg audit), so it should be added.

[root@nixos:/etc/nixos]# vulnix --system
25 derivations with active advisories

ShellCheck-0.10.0
/nix/store/kri201pk61mg0v59b75hxqxrkp7bkfqj-ShellCheck-0.10.0.drv

CVE                                                CVSSv3

https://nvd.nist.gov/vuln/detail/CVE-2021-28794    9.8

async-2.2.5
/nix/store/9x183knps7lcx375ci0n5881li1vr49q-async-2.2.5.drv

CVE                                                CVSSv3

https://nvd.nist.gov/vuln/detail/CVE-2021-43138    7.8

async-2.2.5-r1.cabal
/nix/store/bp7hqj4m5243prcqs5vpcdvx93q3nwjb-async-2.2.5-r1.cabal.drv

CVE                                                CVSSv3

https://nvd.nist.gov/vuln/detail/CVE-2021-43138    7.8

bind-9.18.27
/nix/store/8c7hr5108j2w85gjnf3lngm25s8c9zmy-bind-9.18.27.drv

CVE                                                CVSSv3

https://nvd.nist.gov/vuln/detail/CVE-2019-6470     7.5

busybox-1.36.1
/nix/store/innkpildl5aikyj9ifjs347k1fn1pmng-busybox-1.36.1.drv

CVE                                                CVSSv3

https://nvd.nist.gov/vuln/detail/CVE-2023-42363    5.5

https://nvd.nist.gov/vuln/detail/CVE-2023-42364    5.5

https://nvd.nist.gov/vuln/detail/CVE-2023-42365    5.5

https://nvd.nist.gov/vuln/detail/CVE-2023-42366    5.5

Describe the solution you'd like
Add vulnix to the package audit tools.

Required changes
Extend tests_ports_packages to recognize vulnix is installed on the system