`date_today()` gives suboptimal error

``` r
clock::date_today()
#> Error in `zoned_time_now()`:
#> ! `zone` must be a single string, not absent.
```

<sup>Created on 2024-06-14 with [reprex v2.1.0](https://reprex.tidyverse.org)</sup>

(i.e. the call is wrong)