First step for Python 3.12 support (#5078)

* Mark 3.12

* Update importlib from Python 3.12.0

* Update test_importlib from Python3.12

* Mark failings tests from importlib

* Update test.support from Python3.12

* Fix unsupported parser feature

* mark failing test

* Update functools from Python 3.12

* manual type annotation

* slice behavior changed in 3.12

* empty unittest.main returns non-zero

* test_decimal from CPython 3.12

* Mark failing tests

* Update test_unicode from CPython 3.12

* Update test_functools from Python 3.12

* Update enum from Python 3.12

* enum

* Doc format changed

* Update test_module from CPython

---------

Co-authored-by: CPython developers <>

.github/workflows/ci.yaml

@@ -105,7 +105,7 @@ env:
     test_weakref
     test_yield_from
   # Python version targeted by the CI.
-  PYTHON_VERSION: "3.11.4"
+  PYTHON_VERSION: "3.12.0"
 
 jobs:
   rust_tests:

.github/workflows/cron-ci.yaml

@@ -7,7 +7,7 @@ name: Periodic checks/tasks
 
 env:
   CARGO_ARGS: --no-default-features --features stdlib,zlib,importlib,encodings,ssl,jit
-  PYTHON_VERSION: "3.11.4"
+  PYTHON_VERSION: "3.12.0"
 
 jobs:
   # codecov collects code coverage data from the rust tests, python snippets and python test suite.