zip: Do not fallback to dostime for ctime

On Windows if you write ctime it will change it, while on unix it does not.
So we don't update ctime unless it is part of the archive which is never is.

lib/stdlib/src/zip.erl

@@ -2424,14 +2424,13 @@ file_header_atime_to_datetime(FH) ->
             calendar:system_time_to_local_time(Atime, second)
     end.
 
-%% If we have ctime we use that, otherwise use dos time
+%% Normally ctime will not be set, but if it is we use that. If it is not set
+%% we return undefined so that when we later do write_file_info ctime will remain
+%% the time that the file was created when extracted from the archive.
 file_header_ctime_to_datetime(FH) ->
     #cd_file_header.ctime = #local_file_header.ctime,
     case element(#cd_file_header.ctime, FH) of
-        undefined ->
-            dos_date_time_to_datetime(
-              element(#cd_file_header.last_mod_date, FH),
-              element(#cd_file_header.last_mod_time, FH));
+        undefined -> undefined;
         Ctime ->
             calendar:system_time_to_local_time(Ctime, second)
     end.