I tried to dig it up. I think the terms "version control" and "package management" overlap a lot in how people classify their software or do the histories. They're different with some overlap but it's all muddied up. Interestingly, I found no history in Google of package management from early to modern stuff. There's an interesting project right there for some CompSci student interested in computer archaeology. :)

I did find VC history where the first thing to track software seemed to be SCCC on UNIX:

https://en.wikipedia.org/wiki/Source_Code_Control_System

The rest, from CVS to mainframe stuff to Apollo Aegis's, all showed up around mid-1980's in similar time frame per Wikipedia descriptions. pkg seems strong contender for first, package manager if even version control of source didn't hit others until after its creation.