Bump github-pages-health-check from 1.17.9 to 1.18.1

Bumps [github-pages-health-check](https://github.com/github/github-pages-health-check) from 1.17.9 to 1.18.1.
- [Release notes](https://github.com/github/github-pages-health-check/releases)
- [Commits](github/pages-health-check@v1.17.9...v1.18.1)

---
updated-dependencies:
- dependency-name: github-pages-health-check
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Gemfile

@@ -1,7 +1,7 @@
 source "https://rubygems.org"
 
 gem "jekyll", "3.9.3"
-gem "github-pages-health-check", "1.17.9"
+gem "github-pages-health-check", "1.18.1"
 gem "jekyll-avatar", "0.8.0"
 gem "jekyll-coffeescript", "1.1.1"
 gem "jekyll-commonmark-ghpages", "0.4.0"

Gemfile.lock

@@ -10,12 +10,12 @@ GEM
     colorator (1.1.0)
     commonmarker (0.23.10)
     concurrent-ruby (1.2.2)
-    dnsruby (1.61.9)
-      simpleidn (~> 0.1)
+    dnsruby (1.70.0)
+      simpleidn (~> 0.2.1)
     em-websocket (0.5.3)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0)
-    ethon (0.15.0)
+    ethon (0.16.0)
       ffi (>= 1.15.0)
     eventmachine (1.2.7)
     execjs (2.8.1)
@@ -25,7 +25,7 @@ GEM
     faraday-net_http (3.0.2)
     ffi (1.15.5)
     forwardable-extended (2.6.0)
-    github-pages-health-check (1.17.9)
+    github-pages-health-check (1.18.1)
       addressable (~> 2.3)
       dnsruby (~> 1.60)
       octokit (~> 4.0)
@@ -185,7 +185,7 @@ PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
-  github-pages-health-check (= 1.17.9)
+  github-pages-health-check (= 1.18.1)
   jekyll (= 3.9.3)
   jekyll-avatar (= 0.8.0)
   jekyll-coffeescript (= 1.1.1)