fix(sycl): kernel not found error by forcing -fsycl (#5115)

* chore(sycl): Update oneapi to 2025:1

Signed-off-by: Richard Palethorpe <io@richiejp.com>

* fix(sycl): Pass -fsycl flag as workaround

-fsycl should be set by llama.cpp's cmake file, but something goes wrong
and it doesn't appear to get added

Signed-off-by: Richard Palethorpe <io@richiejp.com>

* fix(build): Speed up llama build by using all CPUs

Signed-off-by: Richard Palethorpe <io@richiejp.com>

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Signed-off-by: Richard Palethorpe <io@richiejp.com>