Backport PR #55907 on branch 2.1.x (DOC: Add release date for 2.1.3) (#55913)

Backport PR #55907: DOC: Add release date for 2.1.3

Co-authored-by: Thomas Li <47963215+lithomas1@users.noreply.github.com>

Author: meeseeksmachine

doc/source/whatsnew/v2.1.3.rst

@@ -1,6 +1,6 @@
 .. _whatsnew_213:
 
-What's new in 2.1.3 (November ??, 2023)
+What's new in 2.1.3 (November 10, 2023)
 ---------------------------------------
 
 These are the changes in pandas 2.1.3. See :ref:`release` for a full changelog
@@ -14,7 +14,6 @@ including other versions of pandas.
 Fixed regressions
 ~~~~~~~~~~~~~~~~~
 - Fixed infinite recursion from operations that return a new object on some DataFrame subclasses (:issue:`55763`)
--
 
 .. ---------------------------------------------------------------------------
 .. _whatsnew_213.bug_fixes:
@@ -25,14 +24,6 @@ Bug fixes
 - Bug in :meth:`Index.isin` raising for Arrow backed string and ``None`` value (:issue:`55821`)
 - Fix :func:`read_parquet` and :func:`read_feather` for `CVE-2023-47248 <https://www.cve.org/CVERecord?id=CVE-2023-47248>`__ (:issue:`55894`)
 
-.. ---------------------------------------------------------------------------
-.. _whatsnew_213.other:
-
-Other
-~~~~~
--
--
-
 .. ---------------------------------------------------------------------------
 .. _whatsnew_213.contributors: