Skip test_config() on Python 3.8

It needs _Py_GetConfig() which was added to Python 3.9.

Author: vstinner

pythoncapi_compat.h

@@ -2213,9 +2213,11 @@ static inline int Py_fclose(FILE *file)
 #endif
 
 
-#if (0x03080000 <= PY_VERSION_HEX \
+#if (0x03090000 <= PY_VERSION_HEX \
      && PY_VERSION_HEX < 0x030E0000 \
      && !defined(PYPY_VERSION) && !defined(Py_LIMITED_API))
+
+// Use the internal C API added to Python 3.9
 PyAPI_FUNC(const PyConfig*) _Py_GetConfig(void);
 
 static inline PyObject*

tests/test_pythoncapi_compat_cext.c

@@ -2224,7 +2224,7 @@ test_file(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
 }
 
 
-#if (0x03080000 <= PY_VERSION_HEX \
+#if (0x03090000 <= PY_VERSION_HEX \
         && !defined(PYPY_VERSION) && !defined(Py_LIMITED_API))
 static PyObject *
 test_config(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
@@ -2695,7 +2695,7 @@ static struct PyMethodDef methods[] = {
     {"test_long_stdint", test_long_stdint, METH_NOARGS, _Py_NULL},
     {"test_structmember", test_structmember, METH_NOARGS, _Py_NULL},
     {"test_file", test_file, METH_NOARGS, _Py_NULL},
-#if (0x03080000 <= PY_VERSION_HEX \
+#if (0x03090000 <= PY_VERSION_HEX \
         && !defined(PYPY_VERSION) && !defined(Py_LIMITED_API))
     {"test_config", test_config, METH_NOARGS, _Py_NULL},
 #endif