Bump octokit from 4.20.0 to 4.21.0 (#13532)

Bumps [octokit](https://github.com/octokit/octokit.rb) from 4.20.0 to 4.21.0.
- [Release notes](https://github.com/octokit/octokit.rb/releases)
- [Changelog](https://github.com/octokit/octokit.rb/blob/4-stable/RELEASE.md)
- [Commits](https://github.com/octokit/octokit.rb/compare/v4.20.0...v4.21.0)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile

@@ -56,7 +56,7 @@ gem "kaminari", "~> 1.2" # A Scope & Engine based, clean, powerful, customizable
 gem "katex", "~> 0.8.0" # This rubygem enables you to render TeX math to HTML using KaTeX. It uses ExecJS under the hood
 gem "liquid", "~> 5.0" # A secure, non-evaling end user template engine with aesthetic markup
 gem "nokogiri", "~> 1.11" # HTML, XML, SAX, and Reader parser
-gem "octokit", "~> 4.20" # Simple wrapper for the GitHub API
+gem "octokit", "~> 4.21" # Simple wrapper for the GitHub API
 gem "oj", "~> 3.11" # JSON parser and object serializer
 gem "omniauth", "~> 2.0" # A generalized Rack framework for multiple-provider authentication
 gem "omniauth-apple", "~> 1.0" # OmniAuth strategy for Sign In with Apple

Gemfile.lock

@@ -268,11 +268,15 @@ GEM
       railties (>= 5.0.0)
     faker (2.17.0)
       i18n (>= 1.6, < 2)
-    faraday (1.3.0)
+    faraday (1.4.1)
+      faraday-excon (~> 1.1)
       faraday-net_http (~> 1.0)
+      faraday-net_http_persistent (~> 1.1)
       multipart-post (>= 1.2, < 3)
-      ruby2_keywords
+      ruby2_keywords (>= 0.0.4)
+    faraday-excon (1.1.0)
     faraday-net_http (1.0.1)
+    faraday-net_http_persistent (1.1.0)
     fastimage (2.2.3)
     fastly (3.0.1)
     feedjira (3.1.2)
@@ -481,7 +485,7 @@ GEM
       multi_json (~> 1.3)
       multi_xml (~> 0.5)
       rack (>= 1.2, < 3)
-    octokit (4.20.0)
+    octokit (4.21.0)
       faraday (>= 0.9)
       sawyer (~> 0.8.0, >= 0.5.3)
     oj (3.11.5)
@@ -925,7 +929,7 @@ DEPENDENCIES
   memory_profiler (~> 1.0)
   nakayoshi_fork (~> 0.0.4)
   nokogiri (~> 1.11)
-  octokit (~> 4.20)
+  octokit (~> 4.21)
   oj (~> 3.11)
   omniauth (~> 2.0)
   omniauth-apple (~> 1.0)