swap file breaks new install

[navels]

Installed latest Raspberry Pi OS (64-bit) Desktop and running the setup script results in

  Installing missing packages: python3-waitress samba samba-common-bin watchdog hostapd dnsmasq
  Stopping memory-intensive services...
  Stopped active services to free memory
  Enabling temporary swap for package installs (1GB)...
  mkdir: cannot create directory ‘/var/swap’: File exists
  dd: failed to open '/var/swap/teslausb_pkg.swap': Not a directory
  ERROR: could not create temporary swap
  ERROR: Failed to enable swap. Cannot proceed.

[navels]

This code needs to run before the early_memory_optimization step:

# Handle legacy /var/swap file (move it aside if it exists as a file)
if [ -f "/var/swap" ] && [ ! -d "/var/swap" ]; then
  echo "  Moving legacy /var/swap file to /var/swap.old..."
  mv /var/swap /var/swap.old
fi