chore: remove broken star history chart embed

Author: w4nderlust

README.md

@@ -349,5 +349,3 @@ ______________________________________________________________________
 <a href="https://github.com/ludwig-ai/ludwig/graphs/contributors">
   <img src="https://contrib.rocks/image?repo=ludwig-ai/ludwig" />
 </a>
-
-[![Star History Chart](https://api.star-history.com/svg?repos=ludwig-ai/ludwig&type=Date)](https://star-history.com/#ludwig-ai/ludwig&Date)