Set enable-experimental-jit=yes-off on Python 3.13+

Author: zanieb

cpython-unix/build-cpython.sh

@@ -424,6 +424,11 @@ if [ -n "${CPYTHON_OPTIMIZED}" ]; then
     if [[ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_12}" && -n "${BOLT_CAPABLE}" ]]; then
         CONFIGURE_FLAGS="${CONFIGURE_FLAGS} --enable-bolt"
     fi
+
+    # Allow users to enable the experimental JIT on 3.13+
+    if [[ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_13}" ]]; then
+        CONFIGURE_FLAGS="${CONFIGURE_FLAGS} --enable-experimental-jit=yes-off"
+    fi
 fi
 
 if [ -n "${CPYTHON_LTO}" ]; then