Docs: Fix external link to devguide.python.org (GH-112899)

Author: hroncok

Doc/whatsnew/3.8.rst

@@ -123,7 +123,7 @@ There is a new function parameter syntax ``/`` to indicate that some
 function parameters must be specified positionally and cannot be used as
 keyword arguments.  This is the same notation shown by ``help()`` for C
 functions annotated with Larry Hastings'
-`Argument Clinic <devguide.python.org/development-tools/clinic/>`__ tool.
+`Argument Clinic <https://devguide.python.org/development-tools/clinic/>`__ tool.
 
 In the following example, parameters *a* and *b* are positional-only,
 while *c* or *d* can be positional or keyword, and *e* or *f* are