Update security_reports_spec.rb

What does this MR do and why?

Describe in detail what your merge request does and why.

As per #348759 (closed)

!76939 (merged) added functionality such that container scanning results appear in the Dependency List. This MR updates the count in the test to include the mocked container scanning results.

Screenshots or screen recordings

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See #348759 (comment 783182715)

How to set up and validate locally

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Run CHROME_HEADLESS=false bundle exec bin/qa Test::Instance::All http://$INSTANCE/ ./qa/specs/features/ee/browser_ui/13_secure/security_reports_spec.rb

MR acceptance checklist

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