Deck calendar integration visibility cannot be toggled for board sharees

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Describe the bug
As a Deck board sharee, I cannot hide calendars. Invoking the usual action ends up with an error (see below).

To Reproduce
Steps to reproduce the behavior:

1. User Alice shares Board Foo with user Bob.
2. User Alice creates some cards with due dates.
3. Alice opens their calendar and sees a list of their calendars, among which there is one called "Deck: Foo". The above set due dates appear in the calendar view as events.
4. Alice clicks on the calendar list entry "Deck: Foo".
5. The entries for "Deck: Foo" are not visible any more, the list entry is greyed out.
6. Bob opens their calendar and sees a list of their calendars, among which there is one called "Deck: Foo". The above set due dates appear in the calendar view as events.
7. Bob clicks on the calendar list entry "Deck: Foo".

Expected behavior
The entries for "Deck: Foo" are not visible any more, the list entry is greyed out.

Actual behavior
The entries for "Deck: Foo" are still visible. The list entry is not greyed out.
An error message appears: An error occured, unable to change visibility of the calendar.

Screenshots

Deck 1.2.2
Calendar 2.1.2
Nextcloud 20.0.4

Reproduce the issue using the listed Deck, Calendar, and Nextcloud versions, following the Alice and Bob sharee steps. Trace the calendar visibility action for a board sharee from the calendar list through the error response. Done means Bob can hide and show the “Deck: Foo” calendar, with the entries and greyed-out state updating without an error.