Yes, you can undo in package mode to undo the update.
You can also update Julia, there isn’t really a reason to stay on 1.7 unless you want to stick with the exact package configuration and setup you had when you originally wrote your code for reproduciblity reasons, but given you updated the packages that doesn’t seem to be the case.
FWIW QuantEcon v0.16.6 works fine on Julia 1.7, so your error is likely coming from elsewhere.