Clean up file parameter tests

[basil]

While testing the upgrade of Commons FileUpload from v1 to v2, I noticed that QueueTest#fileItemPersistence started failing because the v2 DiskFileItem wasn't serializable with XStream, as it trips up JEP-200 class filtering. Looking at what this test does, it seems like a fairly artificial / contrived test. Back when it was added in commit 06d93cb, FileParameterValue was indeed serializing a FileItem to disk, but that behavior was changed in commit 4dde24e, which (as far as I can tell) also broke the ability to queue a build with a file parameter and have that build successfully execute after a restart (since, even though the queue was saved correctly, the FileParameterValue wouldn't have its FileItem after the restart, resulting in a NullPointerException in the BuildWrapper returned by FileParameterValue#createBuildWrapper)—not that anyone seems to have missed this feature in the intervening decade. I tried various things in the UI but could not get a DiskFileItem to be serialized no matter what I tried, so I am concluding that this isn't possible anymore after commit 4dde24e and that QueueTest#fileItemPersistence is a pointless test that can be deleted. I did at least manage to write a test for the scenario described in JENKINS-13536, something that was apparently attempted in commit 4dde24e, though not successfully.

Testing done

mvn clean verify -Dtest=hudson.model.FileParameterValuePersistenceTest

Proposed changelog entries

N/A

Proposed upgrade guidelines

N/A

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Desired reviewers

Pinging @daniel-beck / @jglick for their encyclopedic knowledge of ancient Jenkins history to confirm that my above conclusions are correct

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[jglick]

not that anyone seems to have missed this feature in the intervening decade

And if they did, better to use the file-parameters plugin. The core parameter type has numerous design flaws. Thank you for retroactively adding the test but I would not recommend spending more time on it.

[jglick]

The form of the test looks good; I have never understood how this parameter type is even supposed to work so I cannot judge whether the asserted behavior is the intended behavior.

[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

[daniel-beck]

Belated 👍

which (as far as I can tell) also broke the ability to queue a build with a file parameter and have that build successfully execute after a restart

This also provides an answer to #5174 (comment) -- that it didn't work before anyway. I filed JENKINS-73161 for that (with no plans to pick it up immediately).

[jglick]

jenkinsci/file-parameters-plugin#190 FTR