Flaky timeout on SchedulerTests

[aelovikov-intel]

From #8494 (comment)

The failure (https://github.com/intel/llvm/actions/runs/4296187940) on

Timed Out Tests (1):
  SYCL-Unit :: scheduler/./SchedulerTests/17/19

TIMEOUT: SYCL-Unit :: scheduler/./SchedulerTests/17/19 (465 of 465)
******************** TEST 'SYCL-Unit :: scheduler/./SchedulerTests/17/19' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/__w/llvm/llvm/build/tools/sycl/unittests/scheduler/./SchedulerTests-SYCL-Unit-291055-17-19.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=19 GTEST_SHARD_INDEX=17 /__w/llvm/llvm/build/tools/sycl/unittests/scheduler/./SchedulerTests
--

Note: This is test shard 18 of 19.
[==========] Running 2 tests from 2 test suites.
[----------] Global test environment set-up.
[----------] 1 test from SchedulerTest
[ RUN      ] SchedulerTest.QueueFlushing
[       OK ] SchedulerTest.QueueFlushing (0 ms)
[----------] 1 test from SchedulerTest (0 ms total)

[----------] 1 test from DependsOnTests
[ RUN      ] DependsOnTests.EnqueueNoMemObjDoubleKernelDepHost
[       OK ] DependsOnTests.EnqueueNoMemObjDoubleKernelDepHost (1 ms)
[----------] 1 test from DependsOnTests (1 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 2 test suites ran. (1 ms total)
[  PASSED  ] 2 tests.

--
exit: -9
--
Reached timeout of 600 seconds

can't be related but failing check-sycl results in llvm-test-suite not being run at all, so restarting the whole testing. Writing this comment so that a future github search on the test (if it will fail elsewhere sometime) would point to this run.

[aelovikov-intel]

I haven't seen this for a long time. Also, CI has been refactored so that failing unittest won't prevent e2e from running.