dep: update libxml2 to v2.11.5

https://gitlab.gnome.org/GNOME/libxml2/-/releases/v2.11.5
(cherry picked from commit f7940b7)

CHANGELOG.md

@@ -4,6 +4,19 @@ Nokogiri follows [Semantic Versioning](https://semver.org/), please see the [REA
 
 ---
 
+## next / unreleased
+
+### Dependencies
+
+* [CRuby] Vendored libxml2 is updated to v2.11.5 from v2.11.4. For details please see https://gitlab.gnome.org/GNOME/libxml2/-/releases/v2.11.5
+
+
+### Fixed
+
+* Fixed a typo in a HTML5 parser error message. [[#2927](https://github.com/sparklemotion/nokogiri/issues/2927)] (Thanks, [@anishathalye](https://github.com/anishathalye)!)
+* [CRuby] `ObjectSpace.memsize_of` is now safe to call on `Document`s with complex DTDs. In previous versions, this debugging method could result in a segfault. [[#2923](https://github.com/sparklemotion/nokogiri/issues/2923), [#2924](https://github.com/sparklemotion/nokogiri/issues/2924)]
+
+
 ## 1.15.3 / 2023-07-05
 
 ### Fixed

dependencies.yml

@@ -1,7 +1,7 @@
 libxml2:
-  version: "2.11.4"
-  sha256: "737e1d7f8ab3f139729ca13a2494fd17bf30ddb4b7a427cf336252cab57f57f7"
-  # sha-256 hash provided in https://download.gnome.org/sources/libxml2/2.11/libxml2-2.11.4.sha256sum
+  version: "2.11.5"
+  sha256: "3727b078c360ec69fa869de14bd6f75d7ee8d36987b071e6928d4720a28df3a6"
+  # sha-256 hash provided in https://download.gnome.org/sources/libxml2/2.11/libxml2-2.11.5.sha256sum
 
 libxslt:
   version: "1.1.38"