Update release notes

DimitriPapadopoulos · DimitriPapadopoulos · commit c0e87600d00e · 2023-05-28T12:14:01.000+02:00
diff --git a/docs/release.rst b/docs/release.rst
@@ -11,6 +11,12 @@ Release notes
     Unreleased
     ----------
 
+    Maintenance
+    ~~~~~~~~~~~
+
+    * Change occurrence of io.open() into open().
+      By :user:`Dimitri Papadopoulos Orfanos <DimitriPapadopoulos>` :issue:`1421`.
+
 .. _release_2.15.0:
 
 2.15.0
