build(deps): bump webrick from 1.7.0 to 1.8.1

Bumps [webrick](https://github.com/ruby/webrick) from 1.7.0 to 1.8.1.
- [Release notes](https://github.com/ruby/webrick/releases)
- [Commits](ruby/webrick@v1.7.0...v1.8.1)

---
updated-dependencies:
- dependency-name: webrick
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile

@@ -16,4 +16,4 @@ group :jekyll_plugins do
   gem "jekyll-feed", "~> 0.17.0"
 end
 
-gem "webrick", "~> 1.7.0"
+gem "webrick", "~> 1.8.1"

Gemfile.lock

@@ -68,7 +68,7 @@ GEM
     terminal-table (2.0.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
     unicode-display_width (1.8.0)
-    webrick (1.7.0)
+    webrick (1.8.1)
 
 PLATFORMS
   ruby
@@ -81,7 +81,7 @@ DEPENDENCIES
   jekyll-asciidoc (~> 3.0.0)
   jekyll-feed (~> 0.17.0)
   minima (~> 2.5.1)
-  webrick (~> 1.7.0)
+  webrick (~> 1.8.1)
 
 BUNDLED WITH
    2.3.22