HTML repr is sometimes missing dropdown icon

[jsignell]

I have seen an issue popping up sporadically with the repr_html. I can't reliably reproduce it with jupyterlab 4.1.2 but this is what it looks like:

I think it probably has to do with some css that is getting messed up. In the same environment I don't have a dropdown arrow on regular summary objects either:

<details><summary>Learn more</summary>MORE</details>

Which should look like:

Learn more

MORE

but instead looks like:

[jsignell]

It seems like this is something that happens sporadically in jupyter https://discourse.jupyter.org/t/details-tag-missing-disclosure-triangle/9152

[jsignell]

I tried adding style='display: list-item' but am still seeing this behavior. It's pretty clear that the issue is with jupyterhub, but there still might be something we can do on the pystac side to work around it.