Introduce qlty

[Umekawa]

What

• Calculate and upload code coverage data to qlty during CI
• Make code coverage and Maintainability viewable from the README

How

• Install simplecov_json_formatter
• Change the coverage output format to JSON
• Implement the coverage action from qlty
• Add a badge to the README

Why

• The Code Climate API has been disabled
  • https://docs.qlty.sh/migration/guide

REF

• Remove codeclimate #42

[gemini-code-assist]

Warning

You have reached your daily quota limit. Please wait up to 24 hours and I will start processing your requests again!

[Copilot]

Pull Request Overview

Introduces integration with qlty to publish and display code coverage and maintainability metrics.

• Adds JSON coverage formatter configuration via SimpleCov.
• Adds qlty coverage upload job in GitHub Actions and corresponding badges to the README.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
spec/spec_helper.rb	Adds MultiFormatter including JSON and HTML formatters for coverage output.
graphql-kaminari_connection.gemspec	Adds simplecov_json_formatter as a development dependency.
README.md	Adds Maintainability and Code Coverage badges from qlty.
.github/workflows/test.yml	Adds a separate qlty job to run tests and upload coverage JSON.

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[wataru86]

LGTM!