github_packages: adjust upload retries

[carlocab]

• 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?
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• Have you successfully run brew tests with your changes locally?

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We still regularly see upload failures here, so let's adjust this to see
if we can try to reduce these.

[carlocab]

Also: it would be nice if we had proper logging of these errors, instead of me trying to track down of the number of times I'm CCed...