Mail is not parsing calendar invites

Steps to reproduce

1. Using a third party system (such as Google Calendar), send an invite to your configured email account in NextCloud
2. After the invitation email has been received, click the email in the Mail app
3. Observe that there are no options to accept or decline the invite
4. Go to the Calendar app
5. Observe that the invite does not appear automatically in the calendar

Expected behavior

The Mail app renders a section asking me to accept or decline the event.

The Mail app creates an unaccepted calendar invite in the Calendar app that can be accepted via connected CalDAV clients.

Actual behavior

The Mail app does not display an option to accept or decline an event.

The Calendar app does not show any tentative events.

Mail app version

5.0.0

Nextcloud version

31.0.3

Mailserver or service

Proton Mail (via ProtonMail-Bridge)

Operating system

Unraid

PHP engine version

PHP 8.3

Nextcloud memory caching

No response

Web server

Apache (supported)

Database

PostgreSQL

Additional info

I am not sure if this is similar / a duplicate of #10811

The portion around the Calendar app getting an invite as tentative does seem to duplicate #7750