gpairs benchmark: dpnp on CPU is 2.5 times slower than NumPy 

Results from dpbench of _gpairs_ workload (running on a laptop with 11th Gen processor and Iris Xe graphics):

| workload  | numpy | dpnp CPU | dpnp GPU | size |
| :--- | :---: | :---: | :---: | :---: |
|       gpairs      | 6.6 s  | 15.8 s | 8.6 s | 8192 |

demonstrates dpnp execution time on CPU which is 2.5 times greater than one of NumPy.