chore: update nokogiri to 1.18.3 and remove platform-specific ffi versions

Author: chakravarthik27

docs/Gemfile.lock

@@ -35,8 +35,6 @@ GEM
     faraday-net_http (3.4.0)
       net-http (>= 0.5.0)
     ffi (1.17.1)
-    ffi (1.17.1-arm64-darwin)
-    ffi (1.17.1-x86_64-darwin)
     forwardable-extended (2.6.0)
     gemoji (3.0.1)
     github-pages (226)
@@ -215,18 +213,16 @@ GEM
       rb-inotify (~> 0.9, >= 0.9.10)
     logger (1.6.6)
     mercenary (0.3.6)
+    mini_portile2 (2.8.8)
     minima (2.5.1)
       jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
     minitest (5.25.4)
     net-http (0.6.0)
       uri
-    nokogiri (1.17.2-arm64-darwin)
-      racc (~> 1.4)
-    nokogiri (1.17.2-x86_64-darwin)
-      racc (~> 1.4)
-    nokogiri (1.17.2-x86_64-linux)
+    nokogiri (1.18.3)
+      mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     octokit (4.25.1)
       faraday (>= 1, < 3)
@@ -264,13 +260,11 @@ GEM
     zeitwerk (2.6.18)
 
 PLATFORMS
-  arm64-darwin
-  x86_64-darwin
   x86_64-linux
 
 DEPENDENCIES
   github-pages (= 226)
   webrick (~> 1.7)
 
 BUNDLED WITH
-   2.5.23
+   2.3.7