Merge branch 'main' into tkinter-treeview-9.1

# Conflicts:
#	Doc/whatsnew/3.16.rst

Author: serhiy-storchaka

Doc/deprecations/index.rst

@@ -1,8 +1,6 @@
 Deprecations
 ============
 
-.. include:: pending-removal-in-3.16.rst
-
 .. include:: pending-removal-in-3.17.rst
 
 .. include:: pending-removal-in-3.18.rst
@@ -20,8 +18,6 @@ Deprecations
 C API deprecations
 ------------------
 
-.. include:: c-api-pending-removal-in-3.16.rst
-
 .. include:: c-api-pending-removal-in-3.18.rst
 
 .. include:: c-api-pending-removal-in-3.19.rst

Doc/library/codecs.rst

@@ -1399,6 +1399,14 @@ encodings.
 | punycode           |         | Implement :rfc:`3492`.    |
 |                    |         | Stateful codecs are not   |
 |                    |         | supported.                |
+|                    |         |                           |
+|                    |         | .. warning::              |
+|                    |         |                           |
+|                    |         |    The decoding and       |
+|                    |         |    encoding algorithms    |
+|                    |         |    scale poorly, so       |
+|                    |         |    limit the length of    |
+|                    |         |    untrusted input.       |
 +--------------------+---------+---------------------------+
 | raw_unicode_escape |         | Latin-1 encoding with     |
 |                    |         | :samp:`\\u{XXXX}` and     |