I'm not sure why running old code on an old server that has support for the old code is considered a good thing about PHP. I love BASIC because I can boot up a C64 and the code I wrote 20 years ago still works today!
What's wrong with that? `git pull` to update everything to the latest HEAD, `git co -- HEAD~1` to roll back the latest update, `git diff` to see the latest differences, etc...
This repo doesn't have to be the development repo, just a specialized non-bare repo that's used just for production. It works great for simple sites that don't require extensive deployment infrastructure.