Python_ADDITIONAL_VERSIONS: 3.12 (#4909)

Add 3.12 to the default `Python_ADDITIONAL_VERSIONS`.

Author: ax3l

tools/pybind11Tools.cmake

@@ -43,7 +43,7 @@ endif()
 
 # A user can set versions manually too
 set(Python_ADDITIONAL_VERSIONS
-    "3.11;3.10;3.9;3.8;3.7;3.6"
+    "3.12;3.11;3.10;3.9;3.8;3.7;3.6"
     CACHE INTERNAL "")
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")