pub unsafe extern "C" fn weld_context_free(context: weld_context_t) {
    let context = context as *mut weld::WeldContext;
    if !context.is_null() {
        Box::from_raw(context);
    }
}
Frees a context.

All contexts created by the FFI should be freed. This includes contexts obtained from
`weld_context_new` and `weld_value_context`.
weld-capi/src/lib.rs