Remove unused diffusers/cache_diffusion/pipeline and cuda-python dependency (#984)

`cuda-python` has mixed license and needs EStaff approval for usage. And
till 0.42, it was only used in
`examples/diffusers/cache_diffusion/pipeline` which has not been updated
in 9 months and not used anymore hence removing

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Signed-off-by: Jingyu Xin <jingyux@nvidia.com>
Signed-off-by: Keval Morabia <28916987+kevalmorabia97@users.noreply.github.com>
Co-authored-by: Keval Morabia <28916987+kevalmorabia97@users.noreply.github.com>

Author: jingyu-ml