Track clicks on security training promotion banner CTA

What does this MR do and why?

It adds click-tracking to the security training promotion banner CTA.

Screenshots or screen recordings

No visible changes.

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How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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

Related to #348592 (closed)