ApiClient.getItem makes a GET request to /Items/{itemId} when userId not present, which isn't a valid method

[uwx]

The ApiClient.getItem method makes a GET request to /Items/{itemId} when the userId parameter is not present, which causes a 405 Method Not Allowed response. This function is used by the web player's SyncPlay integration, which prevents SyncPlay from working.

I haven't found a GET /Items/{itemId} endpoint, so I think this isn't an issue with Jellyfin itself but rather with the API client. Note that GET Users/{userId}/Items/{itemId} is an endpoint that exists, and it's what gets used outside of SyncPlay.

Relevant code:

https://github.com/jellyfin/jellyfin-apiclient-javascript/blob/a0143bcd7dc8389c51bcb5cabebcbd1d13e31d49/src/apiClient.js#L782-L794