Enable GPU scenario usage to pytests

[Devjiu]

To enable usage of GPU check python/pyhdk/_sql.pyx and replace CPU to GPU.

--- a/python/pyhdk/_sql.pyx
+++ b/python/pyhdk/_sql.pyx
@@ -92,7 +92,7 @@ cdef class RelAlgExecutor:

   def execute(self, **kwargs):
     cdef const CConfig *config = self.c_rel_alg_executor.get().getExecutor().getConfigPtr().get()
-    cdef CCompilationOptions c_co = CCompilationOptions.defaults(CExecutorDeviceType.CPU)
+    cdef CCompilationOptions c_co = CCompilationOptions.defaults(CExecutorDeviceType.GPU)
     c_co.allow_lazy_fetch = kwargs.get("enable_lazy_fetch", config.rs.enable_lazy_fetch)
     c_co.with_dynamic_watchdog = kwargs.get("enable_dynamic_watchdog", config.exec.watchdog.enable_dynamic)
     cdef unique_ptr[CExecutionOptions] c_eo = make_unique[CExecutionOptions](CExecutionOptions.fromConfig(dereference(config)))

Currently pytest doesn't work with GPU and switching execution back to CPU.

This switching should be done in more convenient and general way.

[Devjiu]

@ienkovich PTAL

[ienkovich]

Covered by #192