It can't be turned off. Once the option for tpms is set in the module it can't be changed. You could try getting another bcm and programming it without tpms if it allows you to select options. Do not buy aftermarket sensors either. Seen to many fail.
'Can't' is probably the wrong word. With enough effort and money, most things can be accomplished.
My advice is to fix it. If you didn't save your sensors, most members report the aftermarket sensors last at least half as long as GM's. My OEM experience is > 8 years, since I've only replaced 1/8. That puts aftermarket life > 4 years.
If $200 for 4 sensors installed ($140 parts & $60 labor) hurts your budget, you may have bought the wrong car.
Today changed the sensors and it worked. The problem is that the wheels were from the export model with TPMS UH3 and my Caddy bought in the U.S. "domestic" model with TPMS UJ6. Already changed tires. Tires in Israel from the heat dries and cracks in 3-4 years. Total paid about $ 1000 ... not so few.