📝 Docs: Remove 'license scan | failing' badge from README.md

[JoshuaKGoldberg]

Documentation Request Checklist

• I have read and agree to Mocha's Code of Conduct and Contributing Guidelines
• I have searched for related issues and issues with the faq label, but none matched my issue.
• I want to provide a PR to resolve this

Overview

This lovely image is in our README.md, including on npm:

It's some kind of "FOSSA Status" badge:

mocha/README.md

Line 10 in b6aa7e8

<a href="https://app.fossa.io/projects/git%2Bhttps%3A%2F%2Fgithub.com%2Fmochajs%2Fmocha?ref=badge_shield"><img src="https://app.fossa.io/api/projects/git%2Bhttps%3A%2F%2Fgithub.com%2Fmochajs%2Fmocha.svg?type=shield" alt="FOSSA Status"></a>

Additional Info

No response