interfaces: T7016: Simplify logic for force deleting dynamic IPv4 address from interface

[indrajitr]

Change summary

Trivial code simplification to #4278.

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)

• T7016: force delete only dynamic IPv4 address from interface #4278

How to test / Smoketest result

Details in #4278

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

[github-actions]

CI integration ❌ failed!

Details

CI logs

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