github: configure cachix/install-nix-action

Signed-off-by: Stefan Kober <stefan.kober@cyberus-technology.de>
On-behalf-of: SAP stefan.kober@sap.com

Author: hertrste

.github/workflows/qa.yml

@@ -14,6 +14,10 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - uses: cachix/install-nix-action@v31
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
+          enable_kvm: true
+          extra_nix_config: "system-features = nixos-test benchmark big-parallel kvm"
       - name: Build
         run: |
           nix build -Lv .#tests.x86_64-linux.openstack-default-setup.driver