#2103 docs/TEST_REQUESTS: an Arc on Windows with and without the Level Zero platform (#1549)

Description

One row for `docs/TEST_REQUESTS.md`: an Arc on Windows with and without the Level Zero platform.

## Why

The OpenCL adapter is the one place where the SYCL Graph extension, oneMKL SYCL BLAS and the free-VRAM query are **all** missing at the same time. I found that on an Arc Pro B70 where the Level Zero loader does not load, so the UR adapters fall back to OpenCL. What I cannot tell from one machine is whether that fallback is a rare driver state or a common one - i.e. whether the OpenCL path is worth maintaining and testing at all.

One report from a Windows Arc that lists `level_zero:gpu`, and one from a Windows Arc that does not, answers it. If Level Zero is normally present, the OpenCL path is an emergency fallback and I would rather know that than keep polishing it. If it is sometimes absent, that is worth a test in CI or at least a documented known-state.

## What I measured, so the row is grounded

Arc Pro B70, 32 GB, Windows 11 24H2, driver 32.0.101.8976, where the Level Zero loader does not load (a V2 loader against a V1-only ICD) and the UR adapters fall back to OpenCL. On that backend:

- oneMKL SYCL BLAS reports that it is not usable on this backend, so the prompt path's expert GEMM fails with a status-999 error unless something else provides it
- `begin_recording` fails with `opencl backend is not supported by SYCL Graph extension`
- `ext_intel_free_memory` answers "not supported", so `get_memory_info` returns 0 - which sizes the expert cache to *nothing*, not to a wrong number

That last one is the reason I am asking rather than just fixing it: an engine that computes 0 free VRAM and then refuses with a message about experts being "neither in VRAM nor mirrored" is pointing at the mirror, not at the figure that answered zero.

## What I did not test

No Level Zero, no CUDA, no HIP, no second Windows Arc, and no Linux. Everything above is one card, one driver, one backend. I am not claiming this state is common - that is the question.

## Note on scope

This touches only `docs/TEST_REQUESTS.md` and adds one row. It is deliberately the smallest possible thing so it can be reviewed or rejected in seconds, independently of any code change I might bring later for the OpenCL path.