ci(github): disable Coverity scan

.github/workflows/analyze-coverity.yaml

@@ -1,8 +1,7 @@
 name: Coverity Scan
 
 on:
-  push:
-    branches: [main]
+  workflow_dispatch:
 
 permissions:
   contents: read

README.md

@@ -7,7 +7,6 @@
 [![Twitter](https://img.shields.io/badge/follow-on%20twitter-1da1f2.svg?style=flat-square)](https://twitter.com/zealdocs)
 
 [![Build Check](https://img.shields.io/github/actions/workflow/status/zealdocs/zeal/build-check.yaml?style=flat-square)](https://github.com/zealdocs/zeal/actions/workflows/build-check.yaml)
-[![Coverity Scan](https://img.shields.io/coverity/scan/4271.svg?style=flat-square)](https://scan.coverity.com/projects/4271)
 
 Zeal is a simple offline documentation browser inspired by [Dash](https://kapeli.com/dash).