Remove unused badge from README

Author: ktbarrett

README.rst

@@ -1,7 +1,3 @@
-.. image:: https://results.pre-commit.ci/badge/github/sphinx-contrib/prettyspecialmethods/master.svg
-    :target: https://results.pre-commit.ci/latest/github/sphinx-contrib/prettyspecialmethods/master
-    :alt: pre-commit.ci status
-
 .. image:: https://github.com/sphinx-contrib/prettyspecialmethods/actions/workflows/tests.yaml/badge.svg?branch=master
     :target: https://github.com/sphinx-contrib/prettyspecialmethods/actions/workflows/tests.yaml
     :alt: Github Actions status