Comment 2 for bug 1997467

Fwiw, runing the same in a 20.04 xenial lxc container:
"""
...
# root@focal:~# netplan get
network:
  version: 2
  ethernets:
    eth0:
      dhcp4: true
  bridges:
    br54:
      dhcp4: false
root@focal:~# apt list netplan.io
Listing... Done
netplan.io/focal-updates,now 0.104-0ubuntu2~20.04.2 amd64 [installed]
"""