Add sycl_ext_oneapi_inter_process_communication to the supported extensions list

The [sycl_ext_oneapi_inter_process_communication](https://github.com/intel/llvm/blob/sycl/sycl/doc/extensions/experimental/sycl_ext_oneapi_inter_process_communication.asciidoc) 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/pytorch/pytorch/blob/release/2.14/c10/xpu/XPUCachingAllocator.cpp#L1863

CC: @gmlueck, @EikanWang, @guangyey

Read the linked sycl_ext_oneapi_inter_process_communication.asciidoc specification first, then inspect the PyTorch XPUCachingAllocator.cpp reference around line 1863. Locate the repository’s supported-extension list and check how experimental extensions are classified. Done means the extension is listed as supported rather than experimental, with its existing usage accounted for.

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