[FIX] developer/reference/cli: --dev=pdb was removed

Does nothing since odoo/odoo#78857 and was removed in odoo/odoo#115076
both in 16.0.

Author: Julien00859

content/developer/reference/cli.rst

@@ -431,9 +431,6 @@ Developer features
 
     * ``qweb``: break in the evaluation of QWeb template when a node contains ``t-debug='debugger'``
 
-    * ``(i)p(u)db``: start the chosen python debugger in the code when an
-      unexpected error is raised before logging and returning the error.
-
     * ``werkzeug``: display the full traceback on the frontend page in case of exception
 
     * ``replica``: simulate :option:`db_replica_host` but connect to the same datbase server as