'upradable' typo for 'upgradeable_dependents'

[papz]

• 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?

---

In reference to #6712

[scpeters]

looks like a minor bug was introduced in #6698

thanks for the fix!

[scpeters]

Thanks so much again for your contribution! Without people like you submitting PRs we couldn't run this project. You rock, @papz!

[MikeMcQuaid]

Thanks for the fix!