Enable Cython test for Python 3.11, using the git master

smoke/venv.sh

@@ -53,6 +53,8 @@ elif [ "$VERSION" == "3.11" ]; then
     # https://github.com/pytest-dev/py/issues/273
     SETUPTOOLS_SCM_PRETEND_VERSION_FOR_PY=1.10.1 python -m pip install https://github.com/pytest-dev/py/archive/refs/heads/master.zip
     python -m pip install pytest
+    # Cython support for 3.11.0a1+ is not yet released
+    python -m pip install https://github.com/cython/cython/archive/master.tar.gz --install-option="--no-cython-compile"
 else
     python -m pip install pytest
     if [ "$PYTHON" != "jython" ]; then
@@ -70,9 +72,7 @@ EOF
 
 python -m pytest -v test_foo.py
 
-# check that we can do extension modules
-# 3.11 problem: https://github.com/cython/cython/issues/4158
-if [ "$PYTHON" != "jython" ] && [ "$VERSION" != "3.11" ]; then
+if [ "$PYTHON" != "jython" ]; then
 cat > module.pyx << EOF
 cdef int add(int a, int b):
     return a + b

tests.yml

@@ -37,6 +37,9 @@
     - smoke39:
         dir: smoke
         run: VERSION=3.9 METHOD=venv ./venv.sh
+    - smoke311:
+        dir: smoke
+        run: VERSION=3.11 METHOD=venv ./venv.sh
     - smoke39_seeder_pip:
         dir: smoke
         run: VERSION=3.9 METHOD=virtualenv-seeder-pip ./venv.sh
@@ -70,6 +73,7 @@
     - python3.7
     - python3.8
     - python3.9
+    - python3.11
     - pypy
     - pypy3
     - python2-devel