From the documentation I can find the "Sharepoint Worker Process Group Update" timer job existed in Sharepoint 2007 but is not a default timer job in any later versions. It's not listed here:
We cannot see it in any 2010, 2013 or 2016 farms bar one 2016 farm where it is listed thousands of times as a one-time job. Whilst we can arrange for these to be deleted we cannot see how they got there? Anyone seen this elsewhere?