No invitation sent to attendees

Summary

No invitation sent

Steps to reproduce

1. Create an event
2. Add attendees
3. Validate

What is the current behavior?

Attendees don't receive any invitation

What is the expected correct behavior?

Attendees receive an invitation, and they can accept or decline

Relevant logs and/or screenshots

Need to be reproduce on our side to be completed.

Possible fixes

Maybe need to have a look at upstream sources. A similar issue was created a long time ago (here), but it is still opened.

Probably related to https://gitlab.e.foundation/e/apps/Calendar/issues/10