You can put flatpak, uv and npm update scripts in /etc/qubes/post-install.d in your templates. In this way, your alternative package managers will perform upgrades when updating through the Qubes Update GUI. Example script for Flatpak that I use (found somewhere on the forums):
#!/bin/sh
# abort if not in a template
if [ "$(qubesdb-read /type)" = "TemplateVM" ]
then
echo "Upgrading flatpak apps..."
export all_proxy=http://127.0.0.1:8082/
flatpak upgrade -y --noninteractive
echo "Done upgrading flatpak apps"
fi