Update typo to address 404 errors in Admin > DevOps Reports page

What does this MR do and why?

This MR addresses a typo in admin/dev_ops_report/show.html.haml that causes a 404 error on dev_ops_reports.css.

This was introduced in !73319 (merged).

Screenshots or screen recordings

How to set up and validate locally

1. Apply EE license
2. Visit /admin/dev_ops_reports
3. Check the Network tab in Developer's Console

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.