Since `231a824`, Notifications do not load on an Iceshrimp.NET server anymore

### Site

dev.phanpy.social

### Version

2025.05.10.231a824

### Instance

shrimp.starlightnet.work

### Browser

- Librewolf 138.0.1-2, FreeDesktop Flatpak runtime, Linux Kernel 6.14.5

### Bug description

The Notifications view will always be empty and say "You're all caught up!" even when there should be notifications.


### To reproduce

1. Login to an Iceshrimp.NET instance with commit `231a824` or later
2. Navigate to notifications tab
3. Observe issue

### Expected behavior

Notifications should continue to show as expected

### Other

I suspect that masto.js might have depracated non-grouped notification endpoints, as that is a recent-ish change that Mastodon did upstream. I'm not sure if that's the case, but if so we might have a compatibility issue here, as IS.NET has not yet implemented the grouped notifications endpoint