Events recurring every last Wednesday of the month are broken

[LeandraH]

Describe the Bug

First described in digitalfabrik/integreat-cms#3022
When setting an event recurring every last Wednesday of the month, it instead shows up as being on the same calendar day as in the first month (e.g. showing up 28.8.24 - correct - 28.9.24 - wrong - 28.10.24 - wrong)

Steps to Reproduce

1. Go to https://cms-test.integreat-app.de/testumgebung/events/de/4601/edit/
2. See that the recurrence rule is set to be every last Wednesday of the month.
3. Go to http://localhost:9000/testumgebung/de/events/test-monthly
4. See that the dates are 28.8., 28.9., 28.10.

Expected Behavior

The dates should be 28.8., 25.9., 30.10.

Actual Behavior

The dates are 28.8., 28.9., 28.10.