[CI] Limit AMD E2E tests to 1 thread (#17422)

There's recurring instabilities on the AMD pre-commit runs, everytime
they fail two things will happen:

* 1 or more test will fail with a memory access fault
* 1 or more test will hang and end up timing out

This seemingly only happens when running the pre-built E2E tests in
parallel.

It is quite difficult to debug and could potentially be an issue in the
AMD drivers.

So as a workaround until we can figure out what's going on, this patch
switches the AMD E2E prebuit tests to run in a single thread.

This is obviously slower than running the tests in parallel, but because
the instability causes hangs that end up hitting the 10 minutes timeout,
a one thread run is faster than a failing multi-thread run. So we get
consistent runs that are slower but may actually end up going through
the job queue faster as they won't be hitting timeouts so often.

On a local setup using the same AMD GPU as the CI:

* Successful multi-thread run:   ~73s
* Successful single-thread run: ~255s
* Failed multi-thread run:       600s+

Author: npmiller

.github/workflows/sycl-linux-precommit.yml

@@ -73,6 +73,7 @@ jobs:
             image_options: -u 1001 --device=/dev/dri --device=/dev/kfd
             target_devices: hip:gpu
             reset_intel_gpu: false
+            extra_lit_opts: -j 1
           - name: Intel Arc A-Series Graphics
             runner: '["Linux", "arc"]'
             image_options: -u 1001 --device=/dev/dri -v /dev/dri/by-path:/dev/dri/by-path --privileged --cap-add SYS_ADMIN