[JENKINS-64356] fix legacyIds missing when creating jobs via REST API or CLI

[mawinter69]

When creating jobs via the rest api or cli the call to onCreatedFromScratch was missing. This can lead to long startup times when many jobs are created this way.

See JENKINS-64356.

Testing done

Unit tests are no longer ignored and succeed

Proposed changelog entries

• Improve startup performance when jobs have been created via REST API or command line interface.

Proposed upgrade guidelines

N/A

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1. The Jira issue, if it exists, is well-described.
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3. There is automated testing or an explanation as to why this change has no tests.
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6. New or substantially changed JavaScript is not defined inline and does not call eval to ease future introduction of Content Security Policy (CSP) directives (see documentation).
7. For dependency updates, there are links to external changelogs and, if possible, full differentials.
8. For new APIs and extension points, there is a link to at least one consumer.

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[MarkEWaite]

Thanks!

[MarkEWaite]

This PR is now ready for merge. We will merge it after approximately 24 hours if there is no negative feedback.

/label ready-for-merge