Remove remaining CodeClimate references (#24289)

.codeclimate.yml

@@ -1,39 +0,0 @@
-version: '2'
-checks:
-  argument-count:
-    enabled: false
-  complex-logic:
-    enabled: false
-  file-lines:
-    enabled: false
-  method-complexity:
-    enabled: false
-  method-count:
-    enabled: false
-  method-lines:
-    enabled: false
-  nested-control-flow:
-    enabled: false
-  return-statements:
-    enabled: false
-  similar-code:
-    enabled: false
-  identical-code:
-    enabled: false
-plugins:
-  brakeman:
-    enabled: true
-  bundler-audit:
-    enabled: false
-  eslint:
-    enabled: false
-  rubocop:
-    enabled: false
-  sass-lint:
-    enabled: false
-exclude_patterns:
-  - spec/
-  - vendor/asset/
-
-  - app/javascript/mastodon/locales/**/*.json
-  - config/locales/**/*.yml

README.md

@@ -6,11 +6,9 @@
 
 [![GitHub release](https://img.shields.io/github/release/mastodon/mastodon.svg)][releases]
 [![Ruby Testing](https://github.com/mastodon/mastodon/actions/workflows/test-ruby.yml/badge.svg)](https://github.com/mastodon/mastodon/actions/workflows/test-ruby.yml)
-[![Code Climate](https://img.shields.io/codeclimate/maintainability/mastodon/mastodon.svg)][code_climate]
 [![Crowdin](https://d322cqt584bo4o.cloudfront.net/mastodon/localized.svg)][crowdin]
 
 [releases]: https://github.com/mastodon/mastodon/releases
-[code_climate]: https://codeclimate.com/github/mastodon/mastodon
 [crowdin]: https://crowdin.com/project/mastodon
 
 Mastodon is a **free, open-source social network server** based on ActivityPub where users can follow friends and discover new ones. On Mastodon, users can publish anything they want: links, pictures, text, video. All Mastodon servers are interoperable as a federated network (users on one server can seamlessly communicate with users from another one, including non-Mastodon software that implements ActivityPub!)