fix: Gemfile & Gemfile.lock to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-RUBY-REXML-7462086

Gemfile

@@ -1,4 +1,4 @@
 source 'https://rubygems.org'
 
-gem 'github-pages', '224'
+gem 'github-pages', '225'
 gem 'foreman'

Gemfile.lock

@@ -1,40 +1,42 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (6.0.5)
+    activesupport (6.0.6.1)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
       zeitwerk (~> 2.2, >= 2.2.2)
-    addressable (2.8.0)
-      public_suffix (>= 2.0.2, < 5.0)
+    addressable (2.8.7)
+      public_suffix (>= 2.0.2, < 7.0)
+    base64 (0.2.0)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
     coffee-script-source (1.11.1)
     colorator (1.1.0)
-    commonmarker (0.23.5)
-    concurrent-ruby (1.1.10)
-    dnsruby (1.61.9)
-      simpleidn (~> 0.1)
+    commonmarker (0.23.10)
+    concurrent-ruby (1.3.3)
+    dnsruby (1.72.2)
+      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)
-    faraday (2.3.0)
-      faraday-net_http (~> 2.0)
+    execjs (2.9.1)
+    faraday (2.8.1)
+      base64
+      faraday-net_http (>= 2.0, < 3.1)
       ruby2_keywords (>= 0.0.4)
-    faraday-net_http (2.0.3)
-    ffi (1.15.5)
+    faraday-net_http (3.0.2)
+    ffi (1.17.0)
     foreman (0.84.0)
       thor (~> 0.19.1)
     forwardable-extended (2.6.0)
     gemoji (3.0.1)
-    github-pages (224)
+    github-pages (225)
       github-pages-health-check (= 1.17.9)
       jekyll (= 3.9.0)
       jekyll-avatar (= 0.7.0)
@@ -85,7 +87,7 @@ GEM
       octokit (~> 4.0)
       public_suffix (>= 3.0, < 5.0)
       typhoeus (~> 1.3)
-    html-pipeline (2.14.2)
+    html-pipeline (2.14.3)
       activesupport (>= 2)
       nokogiri (>= 1.4)
     http_parser.rb (0.8.0)
@@ -204,30 +206,31 @@ GEM
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
     liquid (4.0.3)
-    listen (3.7.1)
+    listen (3.9.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
-    mini_portile2 (2.8.0)
+    mini_portile2 (2.8.7)
     minima (2.5.1)
       jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
-    minitest (5.16.2)
-    nokogiri (1.13.6)
-      mini_portile2 (~> 2.8.0)
+    minitest (5.24.1)
+    nokogiri (1.15.6)
+      mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     octokit (4.25.1)
       faraday (>= 1, < 3)
       sawyer (~> 0.9)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (4.0.7)
-    racc (1.6.0)
-    rb-fsevent (0.11.1)
-    rb-inotify (0.10.1)
+    racc (1.8.0)
+    rb-fsevent (0.11.2)
+    rb-inotify (0.11.1)
       ffi (~> 1.0)
-    rexml (3.2.5)
+    rexml (3.3.2)
+      strscan
     rouge (3.26.0)
     ruby2_keywords (0.0.5)
     rubyzip (2.3.2)
@@ -240,28 +243,25 @@ GEM
     sawyer (0.9.2)
       addressable (>= 2.3.5)
       faraday (>= 0.17.3, < 3)
-    simpleidn (0.2.1)
-      unf (~> 0.1.4)
+    simpleidn (0.2.3)
+    strscan (3.1.0)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
     thor (0.19.4)
     thread_safe (0.3.6)
-    typhoeus (1.4.0)
+    typhoeus (1.4.1)
       ethon (>= 0.9.0)
-    tzinfo (1.2.9)
+    tzinfo (1.2.11)
       thread_safe (~> 0.1)
-    unf (0.1.4)
-      unf_ext
-    unf_ext (0.0.8.2)
     unicode-display_width (1.8.0)
-    zeitwerk (2.6.0)
+    zeitwerk (2.6.16)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   foreman
-  github-pages (= 224)
+  github-pages (= 225)
 
 BUNDLED WITH
    1.17.3