Repin to nixos-24.11 hello for fresh distinct-owner E2E

Author: jasonodoom

.github/workflows/attest.yml

@@ -12,5 +12,5 @@ jobs:
     steps:
       - uses: Ad-Astra-Computing/vega-agent/agent@1f6489e2265219317ae6b7a178602e8625cbd604
         with:
-          installable: "github:NixOS/nixpkgs/64c08a7ca051951c8eae34e3e3cb1e202fe36786#hello"
+          installable: "github:NixOS/nixpkgs/50ab793786d9de88ee30ec4e4c24fb4236fc2674#hello"
           control-plane: https://vega-cache-staging.ad-astra-computing-inc.workers.dev