vpp: T8452: fix typo in variable name

[mihakralj]

Change summary

Fix typo in variable name id_from_persisten_conf → id_from_persistent_conf in src/conf_mode/vpp.py.

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/T8452

Related PR(s)

none

How to test / Smoketest result

This is a variable rename only (no functional change). Verified by grep that zero references to the old name remain:

$ grep -r 'persisten_conf' src/
(no output)

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]

All contributors have signed the CLA ✍️ ✅
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[github-actions]

👍
No issues in PR Title / Commit Title

[mihakralj]

I have read the CLA Document and I hereby sign the CLA

[github-actions]

CI integration ❌ failed!

Details

CI logs

• CLI Smoketests ❌ failed
• CLI Smoketests (interfaces only) 👍 passed
• Config tests 👍 passed
• RAID1 tests 👍 passed
• CLI Smoketests VPP 👍 passed
• Config tests VPP 👍 passed
• TPM tests 👍 passed