specify macos deployment target

Author: jstewmon

.github/workflows/ci.yml

@@ -243,6 +243,7 @@ jobs:
             rustup target add aarch64-apple-darwin
             rustup target add x86_64-apple-darwin
           CIBW_ENVIRONMENT_LINUX: PATH=/root/.cargo/bin:$PATH
+          CIBW_ENVIRONMENT_MACOS: MACOSX_DEPLOYMENT_TARGET=10.12
           CIBW_BUILD: ${{ matrix.py }}-${{ matrix.platform.name }}_*
           CIBW_TEST_COMMAND: python {project}/tests/test_py.py