Made the ISO runner use Arch Linux as a container

.github/workflows/nightly-build.yml

@@ -8,6 +8,10 @@ on:
 jobs:
   build-iso:
     runs-on: ubuntu-latest
+
+    container:
+      image: archlinux/archlinux:latest
+      options: --privileged
     
     steps:
     - name: Checkout repository