Fix: Add year to revision comparison interface timestamps

[Adi-ty]

This PR adds the year to revision timestamps in the "Compare Revisions" interface. The revision comparison interface currently shows dates like "26 Jul @ 11:16" without the year, making it difficult to distinguish between revisions from different years.

Updated the dateShort format in wp_prepare_revisions_for_js() to include the year:

• Before: 'j M @ H:i' → "26 Jul @ 11:16"
• After: 'j M, Y @ H:i' → "26 Jul, 2022 @ 11:16"

Trac ticket: https://core.trac.wordpress.org/ticket/63816

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This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

[gamebits]

Thank you for the swift action on this ticket!

If we're going to stick with the j M Y arrangement (which I recommend!), then I suggest omitting the comma that this PR adds.

[github-actions]

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Props iamadisingh, kgagne.

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[github-actions]

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[github-actions]

A commit was made that fixes the Trac ticket referenced in the description of this pull request.

SVN changeset: 60642
GitHub commit: dd2d7ef

This PR will be closed, but please confirm the accuracy of this and reopen if there is more work to be done.