Upgrade nokogiri to fix security vulnerability

Fix "Nokogiri CSS selector tokenizer has regular expression backtracking" [1].

[1]: https://github.com/freerange/site/security/dependabot/108

Author: floehopper

Gemfile.lock

@@ -182,24 +182,24 @@ GEM
     net-smtp (0.5.0)
       net-protocol
     nio4r (2.7.5)
-    nokogiri (1.19.2)
+    nokogiri (1.19.3)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
-    nokogiri (1.19.2-aarch64-linux-gnu)
+    nokogiri (1.19.3-aarch64-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.19.2-aarch64-linux-musl)
+    nokogiri (1.19.3-aarch64-linux-musl)
       racc (~> 1.4)
-    nokogiri (1.19.2-arm-linux-gnu)
+    nokogiri (1.19.3-arm-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.19.2-arm-linux-musl)
+    nokogiri (1.19.3-arm-linux-musl)
       racc (~> 1.4)
-    nokogiri (1.19.2-arm64-darwin)
+    nokogiri (1.19.3-arm64-darwin)
       racc (~> 1.4)
-    nokogiri (1.19.2-x86_64-darwin)
+    nokogiri (1.19.3-x86_64-darwin)
       racc (~> 1.4)
-    nokogiri (1.19.2-x86_64-linux-gnu)
+    nokogiri (1.19.3-x86_64-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.19.2-x86_64-linux-musl)
+    nokogiri (1.19.3-x86_64-linux-musl)
       racc (~> 1.4)
     pg (1.6.3)
     pg (1.6.3-aarch64-linux)