In many places non-smoking clauses in a tenancy contract are definitely enforced and in some places they're mandatory in some multifamily housing. Even when they're not talking to the neighbors and the manager might clear up the problem, provided you can find a place with stable non-smoking neighbors.

In the short term? Foam insulators for your wall plates will help A LOT to keep the smell from drifting over, and only cost a few dollars and install with just a screwdriver. But you should also discuss the issue with your current landlord, both because they're legally required to keep other tenants from doing things that are detrimental to your quiet enjoyment of the space you pay for, and because your neighbor's place is going to smell to high heaven and the remediation before they can turn it over has a real potential to run into the thousands of dollars.

I lived in Florida for seven years. About 2/3rds or the year our back sliders were open most of the time due to the nice weather. But the neighbor lady smoked liked a chimney. Of course she didn't want smoke in HER house so she would sit on her back porch and smoke. But the prevailing breeze almost always just carried the smoke to my back porch and into our house. Many times on nice days I had close up the house because it would chronically smell like smoke. I never complained because franklly she isn't doing anything illegal or wrong. She was simply sitting on her back porch. I suppose I could have asked her to stop but that seemed rather petty since she's on her own property.

Side note...she was a vegetarian and I loved to smoke meats. So I imagine that she got some 10 hour marathons of smoked meats blowing her way occasionally.