README: Remove PHP badge

Author: lippserd

README.md

@@ -1,6 +1,5 @@
 # Icinga PHP Library - Web Components
 
-[![PHP Support](https://img.shields.io/badge/php-%3E%3D%207.0-777BB4?logo=PHP)](https://php.net/)
 ![Build Status](https://github.com/Icinga/ipl-web/actions/workflows/php.yml/badge.svg)
 
 `ipl/web` provides common web components.