list of acknowledgments for PG16

The list of acknowledgments for the PG16 release notes has been 
committed.  It should show up here sometime: 
<https://www.postgresql.org/docs/16/release-16.html#RELEASE-16-ACKNOWLEDGEMENTS>. 
  As usual, please check for problems such as wrong sorting, duplicate 
names in different variants, or names in the wrong order etc.  (Our 
convention is given name followed by surname.)