en.m.wikipedia.org/wiki/Aluminum_can

The inside of the can is lined by spray coating an epoxy lacquer or polymer to protect the aluminum from being corroded by acidic contents such as carbonated beverages and imparting a metallic taste to the beverage

Guess it depends on your definition of “plastic” and if someone would colloquially refer to an epoxy lining as plastic. Not here to debate word meanings but there is definitely a liner inside aluminum cans.