gh-104773: PEP 594: Remove the sndhdr module

Remove the Lib/test/sndhdrdata/ directory.

Author: vstinner

.gitattributes

@@ -18,7 +18,6 @@
 *.zip binary
 
 # Specific binary files
-Lib/test/sndhdrdata/sndhdr.* binary
 PC/classicAppCompat.* binary
 
 # Text files that should not be subject to eol conversion

Doc/library/sndhdr.rst

@@ -24,7 +24,6 @@ backwards compatibility. They have been superseded by other modules.
    optparse.rst
    ossaudiodev.rst
    pipes.rst
-   sndhdr.rst
    spwd.rst
    sunau.rst
    telnetlib.rst

Doc/library/superseded.rst

@@ -102,6 +102,11 @@ Deprecated
 Removed
 =======
 
+* Remove the ``sndhdr`` module, deprecated in Python 3.11: use the projects
+  `filetype <https://pypi.org/project/filetype/>`_,
+  `puremagic <https://pypi.org/project/puremagic/>`_,
+  or `python-magic <https://pypi.org/project/python-magic/>`_ instead.
+  (Contributed by Victor Stinner in :gh:`104773`.)
 
 
 Porting to Python 3.13