[SYCL][Bindless] Allow 3-channel image formats (#15210)
This patch doesn't implement support for 3-channel formats, it just
allows it in the spec and implementation
so that a backend could implement it later (e.g. Level Zero).
* Removed check from `image_descriptor::verify`
* Updated spec to allow 3-channel formats
* Very simple test, just verifies that CUDA backend still fails
* Missing some PTX intrinsics, use `float4` instead of `float4` when
compiling for CUDA. The more important part is checking that the CUDA
backend throws an exception when trying to create image.
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Co-authored-by: Wenju He <wenju.he@intel.com>
