No alt text on photo galleries

The photo galleries don't have the alt text (as far as I can tell using right-click Inspect Accessibility Properties). 

For example: https://ropensci.org/blog/2023/02/27/runiverse-discovering/
Code with alt: https://github.com/ropensci/roweb3/blob/3764b0a1b7752e3f3c3bbf68119f75c66fe868af/content/blog/2023-02-27-runiverse-discovering/index.md?plain=1#L40