docs: Don't use code formatting for emphasis (GH-30519)

Author: wjandrea

Doc/tutorial/controlflow.rst

@@ -884,7 +884,7 @@ zero or more normal arguments may occur. ::
        file.write(separator.join(args))
 
 
-Normally, these ``variadic`` arguments will be last in the list of formal
+Normally, these *variadic* arguments will be last in the list of formal
 parameters, because they scoop up all remaining input arguments that are
 passed to the function. Any formal parameters which occur after the ``*args``
 parameter are 'keyword-only' arguments, meaning that they can only be used as