Update dependency html-proofer to v5.1.1 (#1660)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

Gemfile.lock

@@ -19,6 +19,7 @@ GEM
       metrics (~> 0.12)
       traces (~> 0.18)
     base64 (0.2.0)
+    benchmark (0.5.0)
     bigdecimal (3.3.1)
     colorator (1.1.0)
     concurrent-ruby (1.3.5)
@@ -48,9 +49,10 @@ GEM
       bigdecimal
       rake (>= 13)
     hashery (2.1.2)
-    html-proofer (5.1.0)
+    html-proofer (5.1.1)
       addressable (~> 2.3)
       async (~> 2.1)
+      benchmark (~> 0.5)
       nokogiri (~> 1.13)
       pdf-reader (~> 2.11)
       rainbow (~> 3.0)
@@ -60,7 +62,7 @@ GEM
     http_parser.rb (0.8.0)
     i18n (1.14.7)
       concurrent-ruby (~> 1.0)
-    io-event (1.14.0)
+    io-event (1.14.2)
     jekyll (4.4.1)
       addressable (~> 2.4)
       base64 (~> 0.2)