If you know that aluminum is your only concern, I wouldn't be too worried about whether your plants would be toxic to eat. Soil in and of itself is already high in aluminum. So, plants are probably pretty good at absorbing only amounts that are needed. However, the form of aluminum may make a difference there. So, it's hard to say for sure.
Now if you were asking whether growing rice in soils high in mercury and arsenic is a good idea, I would give you a resounding no (unless your purpose is to accumulate the metals to help purify the soil and then toss the rice). Some plants do accumulate some metals. It's different for different kinds of plants.
So, I imagine what you're actually growing in these cans makes a big difference as to whether it's safe for you to eat the resulting plants. I don't know about peppers there.
Cans are often lined on the entire inside (not just the lid or some such) with BPA (or a similar chemical), which is a xenoestrogen. And while BPA isn't exactly good for you, this is to prevent too much of the metals from leaching into the can and/or corroding. I don't know that plants accumulate BPA in their fruits, but I have my doubts. The chemicals might affect the plant growth and/or behavior, however. They also put BPA in soda cans (which are full of carbonic acid; I understand that plant roots also produce acids; so, I don't know that they would remove the BPA). Bacteria/fungi in the soil might degrade the BPA faster than the plants, however.