Remove reference to g_product_intelligence group handle in usage ping docs

What does this MR do?

Updates the documentation for implementing usage ping to tell engineers to rely on dangerbot, rather than pinging all engineers in the product intelligence group. This group handle no longer exists anyway.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

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• This change is backwards compatible across updates, or this does not apply.

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Security

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• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
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