openbsm: don’t check for /usr/include/mach/audit_triggers.defs
openbsm: don’t check for /usr/include/mach/audit_triggers.defs

Users with CLT installed in /usr/include have this, but it we don’t
have all of the headers needed in the stdenv.

Fixes #46429

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs