Metal error with Flux image diffusion cast_bf16_f32 does not exist

[super-fun-surf]

Running the new Flux model on Mac M1 Metal

running the example

 cargo run --features metal --example flux -r -- \
    --height 1024 --width 1024 \
    --prompt "a rusty robot walking on a beach holding a small torch, the robot has the word "rust" written on it, high quality, 4k" --model schnell

and after downloading the models and trying to run

Tensor[[1, 768], f32, metal:4294969333]
Error: Metal error Error while loading function: "Function 'cast_bf16_f32' does not exist"

Caused by:
    Error while loading function: "Function 'cast_bf16_f32' does not exist"