Merge pull request #332 from tetengo/doxygen_upgrade

Upgrade the Doxygen version to #330

Author: kaorut

.github/workflows/linux-clang.yml

@@ -16,7 +16,7 @@ env:
   CONCURRENT_BUILD:        4
   CLANG_COMMAND:           clang-14
   CLANGXX_COMMAND:         clang++-14
-  DOXYGEN_VER:             1.11.0
+  DOXYGEN_VER:             1.12.0
   DOXYGEN_CACHE_REV:       0
   BOOST_VER:               1_84_0
   BOOST_VER_DOT:           1.84.0