TOC entries of Domain objects are numbered

[mgeier]

Describe the bug

Follow-up to #10807 (comment).

I'm not sure what's the expected behavior, but it seems strange that a "section" that hasn't a number in the main text has a number in the TOC.

How to Reproduce

conf.py:

# empty

index.rst:

Main Page
=========

.. toctree::
    :numbered:

    domain-objects

domain-objects.rst:

Domain Objects
==============

This section is numbered (as expected).

The following "section" is not numbered, since it isn't really a section
(again, as expected).

However, in the TOC in the sidebar, it is numbered (maybe surprisingly?).

.. py:function:: a_function(an_argument)

    This is a function.

A Subsection
------------

This subsection is numbered (as expected).

Expected behavior

• number in text -> number in TOC.

• numberless in text -> numberless in TOC.

• consecutive numbers in text (not skipping one)

Your project

https://insipid-sphinx-theme.readthedocs.io/en/sphinx5.x/showcase/api-doc.html

Screenshots

OS

any

Python version

any

Sphinx version

5.x branch, after #10807

Sphinx extensions

No response

Extra tools

No response

Additional context

No response