p11-kit: disable tests on darwin
p11-kit: disable tests on darwin

These probably never passed. The test suite was enabled in
c739b09d85d0dab23a9d6ffaef2ec525c28e7086, but fails on macOS/darwin.

Fixes #62614

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