test(packer): configure shared directory directly in the image.

This way, we do not always need to use vagrant to start a vm.

tests/packer/init/debian-server.user-data.yml

@@ -40,6 +40,12 @@ write_files:
     append: true
     content: deb http://deb.debian.org/debian bookworm-backports main contrib non-free
 
+  # Setup shared directory
+  - path: /etc/fstab
+    append: true
+    content: |
+      0a31bc478ef8e2461a4b1cc10a24cc4 /home/user/Projects/apparmor.d  virtiofs defaults  0  1
+
   # Network configuration
   - path: /etc/systemd/network/20-wired.network
     owner: 'root:root'