Fix a few misuses of :option: I missed in r86521.

Extract of the commit message:

  Fix usage of :option: in the docs (#9312).

  :option: is used to create a link to an option of python, not to mark
  up any instance of any arbitrary command-line option.  These were
  changed to ````.
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index d1f47eb..16a753c 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -501,7 +501,7 @@
 ~~~~~~~~~~~~~~~~~~~~
 
 Setting these variables only has an effect in a debug build of Python, that is,
-if Python was configured with the :option:`--with-pydebug` build option.
+if Python was configured with the ``--with-pydebug`` build option.
 
 .. envvar:: PYTHONTHREADDEBUG