pub unsafe extern "C" fn weld_value_free(value: weld_value_t) {
    let value = value as *mut weld::WeldValue;
    if !value.is_null() {
        Box::from_raw(value);
    }
}
Frees a Weld value.

All Weld values must be freed using this call. Weld values which are owned by the runtime also
free the data they contain.  Weld values which are not owned by the runtime only free the
structure used to wrap the data; the actual data itself is owned by the caller.
weld-capi/src/lib.rs