[CRDB-7715] Change date times on jobs page to use 24 hr utc

[jseldess]

Jesse Seldess (jseldess) commented:

PR: cockroachdb/cockroach#68916

From release notes:

Changed date times on the [Jobs Page](../v21.2/ui-jobs-page.html] to use 24-hour UTC. [#68916][#68916)

Jira Issue: DOC-1346

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