fix: issue2551193 - Fix roundup for removal of cgi and cgitb ... standard python modules (and FieldStorage/MiniFieldStorage). Vendor cgi.py and modify imports. Details: roundup/anypy/cgi_.py import that accesses a working cgi.py. All imports dealing with cgi now use cgi_. roundup/anypy/vendored/cgi.py vendored version 2.6 of cgi.py from: https://pypi.org/project/legacy-cgi/ CHANGES.txt change note added COPYING.txt added license for cgi.py doc/rest.txt change example to use cgi_ doc/upgrading.txt doc removal and how to rework local code using cgi.py. frontends/roundup.cgi remove unneeded cgi import roundup/cgi/actions.py roundup/cgi/apache.py roundup/cgi/client.py roundup/cgi/templating.py roundup/cgi/TAL/TALGenerator.py test/db_test_base.py test/rest_common.py test/test_cgi.py remove import cgi and replace with from roundup.anypy.cgi_ import cgi test/test_actions.py test/test_templating.py modify import to get *FieldStorage test/test_admin.py test/test_hyperdbvals.py test/test_xmlrpc.py remove unneeded cgi import

--- a/doc/upgrading.txt	Mon Jul 24 17:19:39 2023 -0400
+++ b/doc/upgrading.txt	Mon Jul 24 17:49:58 2023 -0400
@@ -126,6 +126,21 @@
 
 .. _`information on configuring the API rate limits`: rest.html#rate-limiting-api-failed-logins
 
+Removal of cgi.py from Python (info)
+------------------------------------
+
+The ``cgi.py`` module will be `removed starting with Python 3.13
+<https://peps.python.org/pep-0594/#cgi>`_. Roundup now `vendors a copy
+<https://pypi.org/project/legacy-cgi/>`_ of ``cgi.py`` and makes it
+and its storage objects available by importing from::
+
+   from roundup.anypy.cgi_ import cgi
+   from roundup.anypy.cgi_ import FieldStorage, MiniFieldStorage
+
+It is unlikey that you will care unless you have done some expert
+level Roundup customization. If you have, use one of the imports above
+if you plan on running on Python 3.13 (expected in 2024) or newer.
+
 .. index:: Upgrading; 2.2.0 to 2.3.0
 
 Migrating from 2.2.0 to 2.3.0