Instead of checking for Jython, make it possible to opt-out from the Cython test

- we don't have Jython any more and even if we had, we could explicitly opt out from it
 - we sometimes need to opt out from Cython test in the development versions of Python

smoke/venv.sh

@@ -8,6 +8,7 @@ VERSION=${VERSION:-3.8}
 PYTHON=${PYTHON:-python$VERSION}
 METHOD=${METHOD:-venv}
 TOX=${TOX:-true}
+CYTHON=${CYTHON:-true}
 INSTALL_OR_SKIP=${INSTALL_OR_SKIP:-false}
 
 # clean from possible older runs
@@ -52,10 +53,12 @@ if [ "$VERSION" == "2.6" ]; then
 elif [ "$VERSION" == "3.11" ]; then
     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"
+    if [ "$CYTHON" == "true" ]; then
+        python -m pip install https://github.com/cython/cython/archive/master.tar.gz --install-option="--no-cython-compile"
+    fi
 else
     python -m pip install pytest
-    if [ "$PYTHON" != "jython" ]; then
+    if [ "$CYTHON" == "true" ]; then
         # We try to fetch a wheel only and if that fails, we disable compilation
         # Useful for fresh CPythons, where wheels are not yet ready, but Cython defaults to compiling
         python -m pip install Cython --only-binary :all: || python -m pip install Cython --install-option="--no-cython-compile"
@@ -70,7 +73,7 @@ EOF
 
 python -m pytest -v test_foo.py
 
-if [ "$PYTHON" != "jython" ]; then
+if [ "$CYTHON" == "true" ]; then
 cat > module.pyx << EOF
 cdef int add(int a, int b):
     return a + b

tests.yml

@@ -39,7 +39,7 @@
         run: VERSION=3.9 METHOD=venv ./venv.sh
     - smoke311:
         dir: smoke
-        run: VERSION=3.11 METHOD=venv ./venv.sh
+        run: VERSION=3.11 METHOD=venv CYTHON=false ./venv.sh
     - smoke39_seeder_pip:
         dir: smoke
         run: VERSION=3.9 METHOD=virtualenv-seeder-pip ./venv.sh