T6527: remove legacy packages (backport #680)

[mergify]

Change Summary

Remove legacy packages from ISO build.

• vyatta-cfg-system
• vyatta-op

Are no longer required and migrated to vyos-1y. vyatta-wanloadbalance, vyatta-bash and vyatta-cfg are now a direct dependency of vyos-1x, so everything in one place.

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/T6527

Related PRs

• T6527: remove legacy Perl library components vyatta-cfg#83
• T6527: add legacy Vyatta interpreter files still in use vyos-1x#3745

How to test

Smoketests

Checklist:

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

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This is an automatic backport of pull request #680 done by [Mergify](https://mergify.com).

[github-actions]

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