Update gtest to 1.16.0

Author: rwindegger

conandata.yml

@@ -2,4 +2,4 @@
 # To keep your changes, remove these comment lines, but the plugin won't be able to modify your requirements
 
 requirements:
-  - "gtest/1.15.0"
+  - "gtest/1.16.0"

include/msgpack23/msgpack23.h

@@ -92,7 +92,6 @@ namespace msgpack23 {
     template<typename T>
     concept EmplaceAvailable = requires(T t, typename T::value_type val)
     {
-        // Simply require that calling t.emplace_back(val) is valid
         t.emplace_back(val);
     };