[Core] Fix dtype in InstructPix2Pix SDXL while computing `image_latents` (#5013)
* check out dtypes.
* check out dtypes.
* check out dtypes.
* check out dtypes.
* check out dtypes.
* check out dtypes.
* check out dtypes.
* potential fix
* check out dtypes.
* check out dtypes.
* working?