Remove some wait_for_request calls

What does this MR do and why?

Removes wait_for_request calls from spec/features/admin/admin_abuse_reports_spec.rb.

This file had non-waiting checks immediately following, so we needed to reword them to use waiting ones.

Part of the Remove all uses of `wait_for_requests`, `wait_f... (&22879) effort — the classifier mistakenly decided this would be an "easy" one, but the assertions following the sort_by calls weren't waiting ones, so any existing flakes would be exacerbated, if anything.

How to set up and validate locally

Spec-only.

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