Krita support for generative inpainting has been around since the beginning of the Stable Diffusion craze. It was one of the first AI projects I saved. It definitely predates Photoshop adding it.

Off the top of my head, this plugin is from Nov 6, 2022, and I know there were others before this (or maybe it was just this shared in earlier form). https://github.com/sddebz/stable-diffusion-krita-plugin

Stable Diffusion heralded an explosion in generative AI that predated ChatGPT. Weird how OpenAI got all the credit when it was Stable Diffusion that first opened the gates.