ci: add packer files execute permission

dev/packer/digitalocean.json

@@ -38,6 +38,13 @@
       "source": "scripts/099-one-click",
       "destination": "/etc/update-motd.d/099-one-click"
     },
+    {
+      "type": "shell",
+      "inline": [
+        "chmod +x /var/lib/cloud/scripts/per-instance/001-onboot.sh",
+        "chmod +x /etc/update-motd.d/099-one-click"
+      ]
+    },
     {
       "type": "shell",
       "environment_vars": [