Can you make jerky from stewing chickens?
Sure! You can make jerky out of any meat that isn't too fatty. Jerky is just meat that has been flavored and dried. The drying has to be done with care no matter what kind of meat you use, experimentation is playing with food-safety fire.

Homemade chicken jerky for dogs was loudly in the news a few years ago because a lot of dogs got sick and even mysteriously died after eating chicken jerky dog treats imported from China. To my knowledge, the mystery has never been solved, but a lot of people started making their own chicken jerky at that point.

I have no idea if there is any benefit to using a stewing chicken vs a young chicken for jerky. I rarely see stewing chickens, and if I got a hold of one I'd stew it, but that's just me. At least in the US, they are not common. Where do all the tough old birds go?

The USDA does not endorse using any method for drying other than a dehydrator or an oven. They also (in a step not included in many recipes) recommend fully cooking the meat or poultry before dehydrating. USDA Fact Sheet

Beyond taking proper safety precautions, your choice of meat for jerky is your own. My favorite is salmon.