Get certs from security plugin instead of having them locally checked in

[cwperks]

Description

Download certs from security repo instead of having a local copy in this repo.

Testing out this same pattern that the sql plugin uses to reduce copies of the demo certs across plugin repos.

Check List

• New functionality includes testing.
• New functionality has been documented.
• API changes companion pull request created.
• Commits are signed per the DCO using --signoff.
• Public documentation issue/PR created.

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