Seven and dragon dust. But haven’t used anything since July.
I had to look those up, and I think autocorrect messed with the spellings
Assuming you meant "Sevin" and "Dragoon Dust," I see they both contain carbaryl, and Dragoon Dust also contains copper.
https://www.backyardchickens.com/threads/what-if-chicks-eat-sevin.349041/
https://www.backyardchickens.com/threads/sevin-dust-and-spray-is-it-safe.1162915/
Several threads where people talk about using Sevin on their chickens. Some folks say it's safe to put directly on the chickens or in their dust bath, some say not.
I say that if anyone is dusting a chicken with it, or putting it in the dust bath, then we know the chicken is going to get some in their mouth the next time they preen their feathers.
So I am confident the chickens will not drop dead from any remaining Sevin in the garden. Whether it's a good idea to let them in there, I don't know, but any harm is likely to be relatively small and hard to notice.
I also find that for Sevin, you're supposed to wait various amounts of time to harvest various vegetables. The longest I could find was 21 days for some crops. Since you last applied it in July, and it's now November, that's about four times the maximum wait time, so probably fine for chickens or anything else.
For copper (also an ingredient in Dragoon dust), I can find that some amounts of copper can be toxic to poultry, but I don't think the amount left in the garden after using the pesticide is going to be high enough to hurt the chickens.