ci: enable freethreading for 3.13 in cibuildwheel

Author: cpcloud

.github/workflows/build-wheel.yml

@@ -117,6 +117,7 @@ jobs:
           CIBW_REPAIR_WHEEL_COMMAND_WINDOWS: "delvewheel repair --namespace-pkg cuda -w {dest_dir} {wheel}"
           CIBW_ENVIRONMENT: >
             CUDA_PYTHON_PARALLEL_LEVEL=${{ env.CUDA_PYTHON_PARALLEL_LEVEL }}
+          CIBW_ENABLE: "cpython-freethreading"
         with:
           package-dir: ./cuda_core/
           output-dir: ${{ env.CUDA_CORE_ARTIFACTS_DIR }}
@@ -164,6 +165,7 @@ jobs:
             CUDA_PYTHON_PARALLEL_LEVEL=${{ env.CUDA_PYTHON_PARALLEL_LEVEL }}
           CIBW_BEFORE_BUILD_WINDOWS: "pip install delvewheel"
           CIBW_REPAIR_WHEEL_COMMAND_WINDOWS: "delvewheel repair --namespace-pkg cuda -w {dest_dir} {wheel}"
+          CIBW_ENABLE: "cpython-freethreading"
         with:
           package-dir: ./cuda_bindings/
           output-dir: ${{ env.CUDA_BINDINGS_ARTIFACTS_DIR }}

ci/tools/env-vars

@@ -38,6 +38,7 @@ echo "PYTHON_VERSION_FORMATTED=${PYTHON_VERSION_FORMATTED}" >> $GITHUB_ENV
 
 if [[ "${1}" == "build" ]]; then
   echo "CIBW_BUILD=${CIBW_BUILD}" >> $GITHUB_ENV
+  echo "CIBW_ENABLE=cpython-freethreading" >> $GITHUB_ENV
   CUDA_BINDINGS_ARTIFACT_BASENAME="cuda-bindings-python${PYTHON_VERSION_FORMATTED}-cuda${CUDA_VER}-${HOST_PLATFORM}"
 elif [[ "${1}" == "test" ]]; then
   BUILD_CUDA_MAJOR="$(cut -d '.' -f 1 <<< ${BUILD_CUDA_VER})"