DOC: Set date for 2.2 (pandas-dev#56947)

* DOC: Set date for 2.2

* oops

Author: lithomas1

doc/source/whatsnew/v2.2.0.rst

@@ -1,6 +1,6 @@
 .. _whatsnew_220:
 
-What's new in 2.2.0 (January XX, 2024)
+What's new in 2.2.0 (January 19, 2024)
 --------------------------------------
 
 These are the changes in pandas 2.2.0. See :ref:`release` for a full changelog