[3.12] gh-101100: Fix sphinx warnings in library/asyncio-dev.rst (GH-111179) (#111185)

gh-101100: Fix sphinx warnings in `library/asyncio-dev.rst` (GH-111179)

* gh-101100: Fix sphinx warnings in `library/asyncio-dev.rst`

* Update Doc/library/asyncio-eventloop.rst

* Update Doc/library/asyncio-eventloop.rst

---------

(cherry picked from commit 8c689c9b88)

Co-authored-by: Nikita Sobolev <mail@sobolevn.me>
Co-authored-by: Carol Willing <carolcode@willingconsulting.com>

Doc/library/asyncio-eventloop.rst

@@ -243,7 +243,7 @@ Scheduling callbacks
    See the :ref:`concurrency and multithreading <asyncio-multithreading>`
    section of the documentation.
 
-.. versionchanged:: 3.7
+   .. versionchanged:: 3.7
       The *context* keyword-only parameter was added. See :pep:`567`
       for more details.
 
@@ -1391,6 +1391,14 @@ Enabling debug mode
       The new :ref:`Python Development Mode <devmode>` can now also be used
       to enable the debug mode.
 
+.. attribute:: loop.slow_callback_duration
+
+   This attribute can be used to set the
+   minimum execution duration in seconds that is considered "slow".
+   When debug mode is enabled, "slow" callbacks are logged.
+
+   Default value is 100 milliseconds.
+
 .. seealso::
 
    The :ref:`debug mode of asyncio <asyncio-debug-mode>`.

Doc/tools/.nitignore

@@ -34,7 +34,6 @@ Doc/library/__future__.rst
 Doc/library/abc.rst
 Doc/library/aifc.rst
 Doc/library/ast.rst
-Doc/library/asyncio-dev.rst
 Doc/library/asyncio-eventloop.rst
 Doc/library/asyncio-extending.rst
 Doc/library/asyncio-policy.rst