Improve performance of test_sort_complex_fp_nan

[oleksandr-pavlyk]

This test used to perform numerous operations on very short vectors. The change replaced that with single row-wise operation on matrices.

Now:

(dev_dpctl) opavlyk@opavlyk-mobl:~/repos/dpctl$ SYCL_CACHE_PERSISTENT=1 ONEAPI_DEVICE_SELECTOR=opencl:gpu python -m pytest -v -s ~/repos/dpctl/dpctl/tests/test_usm_ndarray_sorting.py::test_sort_complex_fp_nan
=================================================================================== test session starts ====================================================================================
platform linux -- Python 3.12.3, pytest-8.2.0, pluggy-1.5.0 -- /home/opavlyk/mamba/envs/dev_dpctl/bin/python
cachedir: .pytest_cache
hypothesis profile 'default' -> database=DirectoryBasedExampleDatabase(PosixPath('/home/opavlyk/repos/dpctl/.hypothesis/examples'))
metadata: {'Python': '3.12.3', 'Platform': 'Linux-5.15.146.1-microsoft-standard-WSL2-x86_64-with-glibc2.39', 'Packages': {'pytest': '8.2.0', 'pluggy': '1.5.0'}, 'Plugins': {'json-report': '1.5.0', 'hypothesis': '6.102.4', 'cov': '5.0.0', 'metadata': '3.1.1'}}
rootdir: /home/opavlyk/repos/dpctl
configfile: pyproject.toml
plugins: json-report-1.5.0, hypothesis-6.102.4, cov-5.0.0, metadata-3.1.1
collected 2 items

dpctl/tests/test_usm_ndarray_sorting.py::test_sort_complex_fp_nan[c8] PASSED
dpctl/tests/test_usm_ndarray_sorting.py::test_sort_complex_fp_nan[c16] SKIPPED (Intel(R) Graphics [0x9a49] does not support double precision floating point types)

=============================================================================== 1 passed, 1 skipped in 0.34s ===============================================================================

This single test used to take 3.5 seconds to execute.

• Have you provided a meaningful PR description?
• Have you added a test, reproducer or referred to an issue with a reproducer?
• Have you tested your changes locally for CPU and GPU devices?
• Have you made sure that new changes do not introduce compiler warnings?
• Have you checked performance impact of proposed changes?
• If this PR is a work in progress, are you opening the PR as a draft?

[ndgrigorian]

Good change, improves the performance of the test quite a bit!

[github-actions]

Deleted rendered PR docs from intelpython.github.com/dpctl, latest should be updated shortly. 🤞

[github-actions]

Array API standard conformance tests for dpctl=0.18.0dev0=py310h15de555_32 ran successfully.
Passed: 889
Failed: 12
Skipped: 91

[coveralls]

coverage: 87.911%. remained the same
when pulling 56f6276 on improve-test-sort-complex-fp-nan-performance
into d6d1526 on master.