offboard-spoke.sh: run as root, remove sudo from python3 install

hub/offboard-spoke.sh

@@ -28,8 +28,20 @@ check_deps() {
     fi
 }
 
-if [ "$(id -u)" -eq 0 ]; then
-    die "Run as the hub user, not root."
+[ "$(id -u)" -eq 0 ] || die "Run as root"
+
+if ! command -v python3 >/dev/null 2>&1; then
+    if command -v apt-get >/dev/null 2>&1; then
+        apt-get install -y -q python3
+    elif command -v dnf >/dev/null 2>&1; then
+        dnf install -y -q python3
+    elif command -v yum >/dev/null 2>&1; then
+        yum install -y -q python3
+    elif command -v pacman >/dev/null 2>&1; then
+        pacman -S --noconfirm python
+    else
+        die "python3 not found and no supported package manager to install it"
+    fi
 fi
 
 check_deps rclone crontab python3