Update Doygen to latest version and build under C++23 (#352)

* Update Doygen to latest version and build under C++23

* Comment refers to conflict caused by old Doxygen version

.github/workflows/documentation.yml

@@ -84,7 +84,6 @@ jobs:
           sed -i.backup '1a mold*:build_type=Release' .conan2/profiles/default
           sed -i.backup '1a onetbb*:build_type=Release' .conan2/profiles/default
           sed -i.backup '1a mold*:compiler.libcxx=libstdc++11' .conan2/profiles/default
-          sed -i.backup '1a doxygen*:compiler.cppstd=17' .conan2/profiles/default
 
           echo "tools.cmake.cmaketoolchain:generator = Ninja Multi-Config" >> .conan2/global.conf
           echo "tools.system.package_manager:mode = install" >> .conan2/global.conf

conanfile.py

@@ -83,7 +83,6 @@ class Morpheus(ConanFile):
         "rapidjson/cci.20230929",
         "range-v3/0.12.0",
         "scnlib/2.0.2",
-        #"zlib/1.2.12" # xapian-core/1.4.19' requires 'zlib/1.2.12' while 'boost/1.81.0' requires 'zlib/1.2.13'. To fix this conflict you need to override the package 'zlib' in your root package.
     )
 
     build_requires = (
@@ -144,7 +143,7 @@ def build_requirements(self):
             self.tool_requires("cmake/3.30.1")
 
         if self.options.build_docs:
-            self.build_requires("doxygen/1.9.4") # doxygen/1.9.5 will update dependency on zlib/1.2.12 to zlib/1.2.13
+            self.build_requires("doxygen/1.13.2")
 
         if self.options.get_safe("link_with_mold", False):
             self.build_requires("mold/2.33.0")