cmd/upgrade: comment-out broken_dependents functionality.

[MikeMcQuaid]

This is not a fix for #6671 but will stop people hitting this bug for now.

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same change?
• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes? Here's an example.
• Have you successfully run brew style with your changes locally?
• Have you successfully run brew tests with your changes locally?

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[jonchang]

Can we put this behind a feature flag instead? I've been trying a few things to maybe repro this on my laptop.

[jonchang]

Never mind, I actually can just branch it since I'm inserting logging code anyway. 👍