docs: remove gitter from README (#6640)

It is no longer working.

Author: deevus

README.md

@@ -24,9 +24,6 @@
     <a href="https://discord.gg/s9yRQHt">
         <img src="https://img.shields.io/badge/chat-on%20discord-7289DA.svg" alt="Discord Chat" />
     </a>
-    <a href="https://gitter.im/lukesampson/scoop">
-        <img src="https://badges.gitter.im/lukesampson/scoop.png" alt="Gitter Chat" />
-    </a>
     <a href="./LICENSE">
         <img src="https://img.shields.io/badge/license-UNLICENSE%20or%20MIT-blue" alt="License" />
     </a>