Remove the Go Report Card badge

Go Report Card has shut down. The badge now reads "go report: retired",
and the report page only shows a farewell note. That note recommends
golangci-lint as the replacement, and we already show a badge for it.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

README.md

@@ -45,7 +45,7 @@
 A simple terminal UI for git commands
 <br/>
 
-[![GitHub Releases](https://img.shields.io/github/downloads/jesseduffield/lazygit/total)](https://github.com/jesseduffield/lazygit/releases) [![Go Report Card](https://goreportcard.com/badge/github.com/jesseduffield/lazygit)](https://goreportcard.com/report/github.com/jesseduffield/lazygit) [![golangci-lint](https://img.shields.io/badge/linted%20by-golangci--lint-brightgreen)](https://golangci-lint.run/) [![GitHub tag](https://img.shields.io/github/v/tag/jesseduffield/lazygit?color=blue)](https://github.com/jesseduffield/lazygit/releases/latest) [![homebrew](https://img.shields.io/homebrew/v/lazygit?color=blue)](https://formulae.brew.sh/formula/lazygit)
+[![GitHub Releases](https://img.shields.io/github/downloads/jesseduffield/lazygit/total)](https://github.com/jesseduffield/lazygit/releases) [![golangci-lint](https://img.shields.io/badge/linted%20by-golangci--lint-brightgreen)](https://golangci-lint.run/) [![GitHub tag](https://img.shields.io/github/v/tag/jesseduffield/lazygit?color=blue)](https://github.com/jesseduffield/lazygit/releases/latest) [![homebrew](https://img.shields.io/homebrew/v/lazygit?color=blue)](https://formulae.brew.sh/formula/lazygit)
 
 <!-- demo: commit_and_push -->
 <video src="https://github.com/user-attachments/assets/031799d1-740d-4cda-90cf-689513fa9860" controls></video>