[version.syn] Remove mention of nonexistent header <priority_queue>

Author: cpplearner

source/support.tex

@@ -605,7 +605,7 @@
 #define @\defnlibxname{cpp_lib_constexpr_vector}@                  201907L // also in \libheader{vector}
 #define @\defnlibxname{cpp_lib_containers_ranges}@                 202202L
   // also in \libheader{vector}, \libheader{list}, \libheader{forward_list}, \libheader{map}, \libheader{set}, \libheader{unordered_map}, \libheader{unordered_set},
-  // \libheader{deque}, \libheader{queue}, \libheader{priority_queue}, \libheader{stack}, \libheader{string}
+  // \libheader{deque}, \libheader{queue}, \libheader{stack}, \libheader{string}
 #define @\defnlibxname{cpp_lib_coroutine}@                         201902L // also in \libheader{coroutine}
 #define @\defnlibxname{cpp_lib_destroying_delete}@                 201806L // also in \libheader{new}
 #define @\defnlibxname{cpp_lib_enable_shared_from_this}@           201603L // also in \libheader{memory}