Bump jekyll from 4.2.0 to 4.2.1

Bumps [jekyll](https://github.com/jekyll/jekyll) from 4.2.0 to 4.2.1.
- [Release notes](https://github.com/jekyll/jekyll/releases)
- [Changelog](https://github.com/jekyll/jekyll/blob/master/History.markdown)
- [Commits](https://github.com/jekyll/jekyll/compare/v4.2.0...v4.2.1)

---
updated-dependencies:
- dependency-name: jekyll
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -50,7 +50,7 @@ GEM
     execjs (2.7.0)
     faraday (1.0.1)
       multipart-post (>= 1.2, < 3)
-    ffi (1.15.3)
+    ffi (1.15.4)
     forwardable-extended (2.6.0)
     gemoji (3.0.1)
     html-pipeline (2.13.0)
@@ -67,7 +67,7 @@ GEM
     http_parser.rb (0.6.0)
     i18n (1.8.10)
       concurrent-ruby (~> 1.0)
-    jekyll (4.2.0)
+    jekyll (4.2.1)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
@@ -220,7 +220,7 @@ GEM
       ethon (>= 0.9.0)
     tzinfo (2.0.4)
       concurrent-ruby (~> 1.0)
-    unicode-display_width (1.7.0)
+    unicode-display_width (1.8.0)
     yell (2.2.2)
     zeitwerk (2.4.2)