Claim Python 3.11 support and add tests (#9471)

* set up 3.11 tests

* fixup warnings

* sed -i "s/\( *'Pro.*3\.1\)0\(',\)/\10\2\n\11\2/" */setup.py

* update changelog

pytest.ini

@@ -18,8 +18,11 @@
 #    https://github.com/boto/botocore/issues/2550.
 # 3) pytest-cov uses deprecated functionality in pytest-xdist, to be resolved by
 #    https://github.com/pytest-dev/pytest-cov/issues/557.
+# 4) botocore is currently using the cgi module which will be removed from
+#    Python in version 3.13. See https://github.com/boto/botocore/issues/2803.
 filterwarnings =
     error
     ignore:decodestring\(\) is a deprecated alias:DeprecationWarning:dns
     ignore:'urllib3.contrib.pyopenssl:DeprecationWarning:botocore
     ignore:.*rsyncdir:DeprecationWarning
+    ignore:'cgi' is deprecated:DeprecationWarning:botocore