Remove branch protection from SKC master

It will be a while before CI is up and running on the master branch of
SKC, especially the AIO jobs. This change removes all required status so
merges are not blocked. Changes still require approval from the kayobe
team.

Author: Alex-Welsh

terraform/github/terraform.tfvars.json

@@ -369,7 +369,8 @@
         "aio upgrade (Ubuntu Jammy OVS) / All in one",
         "Ansible 2.15 lint with Python 3.10",
         "Ansible 2.16 lint with Python 3.12"
-      ]
+      ],
+      "stackhpc/master": []
     },
     "stackhpc-release-train": {
       "default": [