This api variable might be used. These usecases might be broken by this update. Did you check for usages in the Dodona codebase?

We should probably also check for usecases in the VSCode and jetbrains plugins. I know at least one of them checks for notifications

I didn't think of the codebase using those functions. That is now fixed (it was used in 4 places, according to RubyMine).

I will see if I can find the usage of notifiable_url in the VSCode and Jetbrains plugins.

Edit:
thepieterdc's plugins for JetBrains don't appear to be using this.
xerbalind's plugin for neovim doesn't do anything with notifications.
gubogaer's plugin for Rstudio doesn't appear to do anything with notifications.
Dodona's plugin for creating exercises in VSCode doesn't appear to be using it either.

Maybe it is used in thepieterdc's plugin for VSCode, but the api-key (notifiable_url) is not called explicitly:

export function openNotifications() {
    const url = Uri.parse(`${getEnvironmentUrl()}/notifications`);
    commands.executeCommand("vscode.open", url);
}

I thought checks didn't run automatically when someone outside the Dodona team pushed a commit to their PR, and it's even on a draft PR?