When trying to import an ICS file attached to an email no calendars are found

## What Happened
Not sure if this is a Calendar issue or a Mail but I decided to open it for Calendar. If that's not the case, just let me know and I will open it for Mail instead.

When trying to import an ICS file attached to an e-mail, Calendar opens, the "Select a calendar to import into" dialog opens, but no calendars are listed and the search doesn't return any results for known calendars so the event cannot be imported.
On the other hand if I save the ICS file attached to the e-mail, to disk and then I open the ICS file by clicking on it, Calendar opens, the "Select a calendar to import into" dialog opens and my calendar is listed without even having to search for it.

## Expected Behavior
When clicking on the ICS file attached to the email Calendar opens, the "Select a calendar to import into" dialog opens and my calendar is listed without even having to search for it.

## Steps to Reproduce
1. Make sure Calendar is not running.
2. Open the Mail app
3. Select an e-mail with an ICS file attached
4. Clic on the ICS file to open it
5. Wait for Calendar to open and the "Select a calendar to import into" dialog to appear.
6. No calendar is listed and searching doesn't bring any results.

### Logs

## Platform Information
elementary OS 6 Odin
Calendar version: maya-calendar/focal,now 6.0.1+r2122+pkg137\~ubuntu6.1
Mail version: io.elementary.mail/focal,now 6.1.1+r701+pkg24\~ubuntu6.1

EDIT: add an additional step in repro according to my comment below.

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