T7016: force delete only dynamic IPv4 address from interface

[yzguy]

Change summary

#4250 introduced a bug that attempts to delete dynamic IPv6 addresses on an interface when that interface is being removed from being a DHCP client. The prefix length is not passed to the ip del command so therefore it fails to delete it throwing an exception

The issue seems to be:

1. IPv6 addresses are not supposed to be deleted when IPv4 DHCP client is removed from the interface
2. If an IPv4 address is being deleted, it needs it's CIDR to be passed to ip del for it to successfully delete it

Traceback (most recent call last):
  File "/usr/libexec/vyos/services/vyos-configd", line 139, in run_script
    script.apply(c)
  File "/usr/libexec/vyos//conf_mode/interfaces_ethernet.py", line 336, in apply
    e.update(ethernet)
  File "/usr/lib/python3/dist-packages/vyos/ifconfig/ethernet.py", line 532, in update
    super().update(config)
  File "/usr/lib/python3/dist-packages/vyos/ifconfig/interface.py", line 1663, in update
    self.del_addr('dhcp')
  File "/usr/lib/python3/dist-packages/vyos/ifconfig/interface.py", line 1280, in del_addr
    self.set_dhcp(False)
  File "/usr/lib/python3/dist-packages/vyos/ifconfig/interface.py", line 1430, in set_dhcp
    self.del_addr(address)
  File "/usr/lib/python3/dist-packages/vyos/ifconfig/interface.py", line 1285, in del_addr
    self._cmd(f'{netns_cmd} ip addr del {addr} dev {self.ifname}')
  File "/usr/lib/python3/dist-packages/vyos/ifconfig/control.py", line 64, in _cmd
    return cmd(command, self.debug)
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/vyos/utils/process.py", line 155, in cmd
    raise OSError(code, feedback)
FileNotFoundError: [Errno 2] failed to run command:  ip addr del 2600:3c0e::f03c:93ff:fed7:f58a dev eth0
returned:
exit code: 2

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

• https://vyos.dev/T7016
• https://vyos.dev/T6972

Related PR(s)

• ifconfig: T6972: smoketests fail as IP address is not removed in time #4250

How to test / Smoketest result

set interfaces ethernet eth0 address 'dhcp'
set interfaces ethernet eth0 ipv6 address autoconf

Ensure you have an IPv4/IPv6 address from DHCP/SLAAC on eth0

Then try to remove DHCP client

delete interfaces ethernet eth0 address dhcp
compare
commit

The IPv6 address will try and be deleted but fails due to missing prefix length, causing an exception to be thrown

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[github-actions]

👍
No issues in PR Title / Commit Title

[yzguy]

Fixed the commit message to have the correct task ID

[github-actions]

CI integration ❌ failed!

Details

CI logs

• CLI Smoketests (no interfaces) ❌ failed
• CLI Smoketests (interfaces only) 👍 passed
• Config tests 👍 passed
• RAID1 tests 👍 passed
• TPM tests 👍 passed