DOC: update what's new date for final release date

ksunden · ksunden · commit ddef53603582 · 2023-02-13T14:22:13.000-06:00
diff --git a/doc/users/prev_whats_new/whats_new_3.7.0.rst b/doc/users/prev_whats_new/whats_new_3.7.0.rst
@@ -1,5 +1,5 @@
 =============================================
-What's new in Matplotlib 3.7.0 (Feb 10, 2023)
+What's new in Matplotlib 3.7.0 (Feb 13, 2023)
 =============================================
 
 For a list of all of the issues and pull requests since the last revision, see
