Add index variable to forEach loop in queue-items.jelly

[duemir]

Fixes a regression in the Build History widget when all the queued tasks show up with the same number. Which I think fixes #16748

Testing done

1. Create a hello world pipeline that sleeps for 5 minutes. Disable concurrency. Add a parameter.
2. Trigger a pipeline build. Ensure it works and sleeps
3. Trigger more pipelines; give each a unique parameter

Expected: Build history shows a unique incremental number for each queued pipeline task
Actual: All queued tasks show the same number

Screenshots (UI changes only)

Before

After

Proposed changelog entries

• Fix estimated build number in Build History widget

Proposed changelog category

/label bug

Proposed upgrade guidelines

N/A

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Desired reviewers

@mention

Before the changes are marked as ready-for-merge:

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[duemir]

JEXL on line 46 uses variable i.

[gbhat618]

L46

[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

[MarkEWaite]

Merging now so that it will be included in weekly 2.552.