Add sycl_ext_oneapi_work_group_scratch_memory to the supported extensions list

[dvrogozh]

The sycl_ext_oneapi_work_group_scratch_memory is currently experimental extension while actual products such as Pytorch rely on it in the shipped products. Can this extension be promoted from experimental to supported?

See: https://github.com/intel/torch-xpu-ops/blob/release/2.14/src/comm/SYCLHelpers.h#L288
CC: @gmlueck, @EikanWang, @guangyey

[gmlueck]

We have discussed this already with the Khronos WG, and there is no opposition to making it a KHR.

This extension has a dependency on "properties", though, so we first need to make a KHR for properties. That is already in progress (KhronosGroup/SYCL-Docs#980).

[dvrogozh]

Proposing and accepting new KHR extensions by Khronos takes significant time while we have production deliveries on the market (Pytorch) requiring this extension. Extension is available as experimental from Dec 4, 2024. Can it be marked as supported now?