[JENKINS-64553] fix ItemListener not called after updating job via REST API or CLI

[mawinter69]

when a job is updated via REST API or CLI, the
ItemListener.fireOnUpdated is now called to inform about the change.

See JENKINS-64553.

Testing done

added a Unit test that verifies ItemListener is called. Without the change the test fails.

Proposed changelog entries

• Consistently notify job listeners when the job definition is updated from the REST API or command line interface.

Proposed upgrade guidelines

N/A

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[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

[mawinter69]

@krisstern This might be a candidate for the next LTS 2.452.2

[krisstern]

Hi @mawinter69,
Sure, let me add this to the backporting of LTS 2.452.2 soon.

[jglick]

Note: this does not suffice for onUpdated to be called from other code that happens to save a Job (e.g., adding/removing JobPropertys). Perhaps the existing fireOnUpdated call sites should be deleted and replaced with one call from

jenkins/core/src/main/java/hudson/model/AbstractItem.java

Line 617 in 9b1b1c6

SaveableListener.fireOnChange(this, getConfigFile());

regardless of the save’s origin.