What were you trying to do that didn't work?

When a NM connection holding non-infinity `ipv4.dhcp-timeout`, the connection will be deactivated on DHCP timeout, when nmstate modifying this NM connection, it should also fix `ipv4.dhcp-timeout` to make sure it never been deactivated due to timeout even when ipv4 not mentioned in desired state.

Please provide the package NVR for which bug is seen:

nmstate-2.2.19-1.el9.x86_64

How reproducible:

100%

Steps to reproduce

#!/bin/bash

nmcli c del dummy1

nmcli c add type dummy ifname dummy1 connection.id dummy1  \
    ipv4.method auto ipv4.dhcp-timeout 5 \
    ipv6.method auto ipv6.dhcp-timeout 5

echo '
---
interfaces:
- name: dummy1
  description: Test Dummy
' | nmstatectl set -
sleep 120

ip link show dummy1

Expected results

The `dummy1` exists after DHCP timeout(2 minutes)

Actual results

The `dummy1` not exists after DHCP timeout(2 minutes)