remove codacy badge

Author: zhengp0

README.md

@@ -3,7 +3,6 @@
 [![build](https://img.shields.io/github/actions/workflow/status/ihmeuw-msca/xspline/python-build.yml?branch=main)](https://github.com/ihmeuw-msca/xspline/actions)
 [![docs](https://img.shields.io/badge/docs-here-green)](https://ihmeuw-msca.github.io/xspline)
 [![codecov](https://img.shields.io/codecov/c/github/ihmeuw-msca/xspline)](https://codecov.io/gh/ihmeuw-msca/xspline)
-[![codacy grade](https://img.shields.io/codacy/grade/f1646d62d6764e77a59d6c71df262ed4)](https://app.codacy.com/gh/ihmeuw-msca/xspline/dashboard?utm_source=gh&utm_medium=referral&utm_content=&utm_campaign=Badge_grade)
 
 
 # XSpline