Force QEMU secure boot tests to AX161 hardware

Signed-off-by: Kyle Harding <[email protected]>

.github/workflows/generic-amd64.yml

@@ -64,11 +64,12 @@ jobs:
       # Sign image for secure boot
       sign-image: true
       # Use QEMU workers for testing and run cloud suite against balenaCloud production
+      # Pin to AX161 workers for QEMU secure boot testing.
       test_matrix: >
         {
           "test_suite": ["os","cloud","hup"],
           "environment": ["balena-cloud.com"],
           "worker_type": ["qemu"],
-          "runs_on": [["self-hosted", "X64", "kvm", "yocto"]],
+          "runs_on": [["self-hosted", "X64", "kvm", "board:Pro_WS_665-ACE"]],
           "secure_boot": ["sb",""]
         }