chore: Remove codebeat badge (#5618)

Codebeat is shutting down see https://codebeat.co/. Let's remove the
badge.

Author: philipphofmann

README.md

@@ -9,7 +9,6 @@ _Bad software is everywhere, and we're tired of it. Sentry is on a mission to he
 # Official Sentry SDK for iOS / tvOS / macOS / watchOS <sup>(1)</sup>
 
 [![Build](https://img.shields.io/github/actions/workflow/status/getsentry/sentry-cocoa/build.yml?branch=main)](https://github.com/getsentry/sentry-cocoa/actions/workflows/build.yml?query=branch%3Amain)
-[![codebeat badge](https://codebeat.co/badges/07f0bc91-9102-4fd8-99a6-30b25dc98037)](https://codebeat.co/projects/github-com-getsentry-sentry-cocoa-master)
 [![codecov.io](https://codecov.io/gh/getsentry/sentry-cocoa/branch/master/graph/badge.svg)](https://codecov.io/gh/getsentry/sentry-cocoa)
 [![CocoaPods compadible](https://img.shields.io/cocoapods/v/Sentry.svg)](https://cocoapods.org/pods/Sentry)
 [![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/Carthage/Carthage)