Remove dead badge on README.md (#17261)

Author: 6543

README.md

@@ -12,9 +12,6 @@
   <a href="https://discord.gg/Gitea" title="Join the Discord chat at https://discord.gg/Gitea">
     <img src="https://img.shields.io/discord/322538954119184384.svg">
   </a>
-  <a href="https://microbadger.com/images/gitea/gitea" title="Get your own image badge on microbadger.com">
-    <img src="https://images.microbadger.com/badges/image/gitea/gitea.svg">
-  </a>
   <a href="https://codecov.io/gh/go-gitea/gitea" title="Codecov">
     <img src="https://codecov.io/gh/go-gitea/gitea/branch/main/graph/badge.svg">
   </a>