Gobolinux comes to mind.

If you don't mind a very limited set of software, the way tinycorelinux is setup can also allow multiple different tcz installed

These two Linux distros essentially allow two different versions of same software/libraries (glibc/python whatever) installed

(Gobolinux explicitly states that whereas I find it to be an unintended but elegant consequence for tinycorelinux but I recommend taking a look at Gobolinux)