I donāt have init-zsh.sh on my Mac either. I donāt know why Docker would add it, but that is probably added only when Docker Desktop is installed. Have you tried to delete that line?
One thing I can imagine is that Docke provides a way to run that script optionally if that exists. Because of || true at the end, it will not break your zshrc but the error message will still appear. The correct way to make it optional would be something like this:
source /Users/jeff/.docker/init-zsh.sh 2>/dev/null || true # Added by Docker Desktop
which redirects the error message to /dev/null. Maybe I donāt have that line because I installed Docker Desktop many versions ago.
On second thought, hiding the error messages might not be the best idea as it would hide the error messages shown by commands actually running in an existing init-zsh script, but you could just create an empty script.