gateway4 has been deprecated, use default routes instead.

Ubuntu 22.04 LTS was released and I immediately installed and ran the server.
I set a fixed IP address during installation, but it was wrong, so I corrected it and was told that gateway4 is deprecated.

Here is the actual message displayed.

$ sudo netplan apply

** (generate:1170): WARNING **: 04:03:00.838: `gateway4` has been deprecated, use default routes instead.
See the 'Default routes' section of the documentation for more details.

** (process:1168): WARNING **: 04:03:01.436: `gateway4` has been deprecated, use default routes instead.
See the 'Default routes' section of the documentation for more details.

There seems to be a new way to write.
UNIX&LINUX / netplan generate: `gateway4` has been deprecated, use default routes instead

# This is the network config written by 'subiquity'
network:
  ethernets:
    ens33:
      addresses:
      - 192.168.110.5/24
      - fdnn:nnnn:nnnn:nnnn:nnnn:nnnn:110:5/64
#     gateway4: 192.168.110.1
      routes:
        - to: default
          via: 192.168.110.1
#       - to: 10.20.20.0/24
#         via: 192.168.110.6
#       - to: default
#         via: fdnn:nnnn:nnnn:nnnn:nnnn:nnnn:110:1
      nameservers:
        addresses:
        - 192.168.110.2
        - fdnn:nnnn:nnnn:nnnn:nnnn:nnnn:110:2
        search:
        - hogeserver.hogeddns.jp
  version: 2

* In our network, the IPv6 one is not routed anywhere. I just looked up how to write it down and am leaving it as a note.
* The 10.20.20.0/24 is a setting I added when I tried OpenStack and wanted to send packets to 192.168.110.6.

After the modification, the setup was completed without displaying any errors.

$ sudo netplan apply

This, too, will be set up correctly by the installer someday.