Added linetrace=true Cython directive to all .pyx files

This is safe to do per

https://cython.readthedocs.io/en/latest/src/tutorial/profiling_tutorial.html#enabling-line-tracing

Its use allows improved coverage testing of Cython modules when Cython
sources are compiled with CYTHON_TRACE/CYTHON_TRACE_NOGIL preprocessor
variables defined.

Author: oleksandr-pavlyk

dpctl/_sycl_context.pyx

@@ -16,6 +16,7 @@
 
 # distutils: language = c++
 # cython: language_level=3
+# cython: linetrace=True
 
 """ Implements SyclContext Cython extension type.
 """

dpctl/_sycl_device.pyx

@@ -16,6 +16,7 @@
 
 # distutils: language = c++
 # cython: language_level=3
+# cython: linetrace=True
 
 """ Implements SyclDevice Cython extension type.
 """

dpctl/_sycl_device_factory.pyx

@@ -16,6 +16,7 @@
 
 # distutils: language = c++
 # cython: language_level=3
+# cython: linetrace=True
 
 """ This module implements several device creation helper functions:
 

dpctl/_sycl_event.pyx

@@ -16,6 +16,7 @@
 
 # distutils: language = c++
 # cython: language_level=3
+# cython: linetrace=True
 
 """ Implements SyclEvent Cython extension type.
 """

dpctl/_sycl_platform.pyx

@@ -16,6 +16,7 @@
 #
 # distutils: language = c++
 # cython: language_level=3
+# cython: linetrace=True
 
 """ Implements SyclPlatform Cython extension type.
 """

dpctl/_sycl_queue.pyx

@@ -16,6 +16,7 @@
 
 # distutils: language = c++
 # cython: language_level=3
+# cython: linetrace=True
 
 """ Implements SyclQueue Cython extension type.
 """

dpctl/_sycl_queue_manager.pyx

@@ -16,6 +16,7 @@
 #
 # distutils: language = c++
 # cython: language_level=3
+# cython: linetrace=True
 
 from __future__ import print_function
 

dpctl/memory/_memory.pyx

@@ -16,6 +16,7 @@
 
 # distutils: language = c++
 # cython: language_level=3
+# cython: linetrace=True
 
 """This file implements Python buffer protocol using Sycl USM shared and host
 allocators. The USM device allocator is also exposed through this module for

dpctl/program/_program.pyx

@@ -16,6 +16,7 @@
 
 # distutils: language = c++
 # cython: language_level=3
+# cython: linetrace=True
 
 """Implements a Python interface for SYCL's program and kernel runtime classes.
 

dpctl/tensor/_usmarray.pyx

@@ -16,6 +16,7 @@
 
 # distutils: language = c++
 # cython: language_level=3
+# cython: linetrace=True
 
 import numpy as np