Close #14309: Deprecate time.clock()

Use time.perf_counter() or time.process_time() instead.
diff --git a/Doc/library/time.rst b/Doc/library/time.rst
index 56ca865..879f8c7 100644
--- a/Doc/library/time.rst
+++ b/Doc/library/time.rst
@@ -136,6 +136,11 @@
    :c:func:`QueryPerformanceCounter`. The resolution is typically better than one
    microsecond.
 
+   .. deprecated:: 3.3
+      The behaviour of this function depends on the platform: use
+      :func:`perf_counter` or :func:`process_time` instead, depending on your
+      requirements, to have a well defined behaviour.
+
 
 .. function:: clock_getres(clk_id)