No membership event in check_event_for_spam

### Description

Hi,

I was working on the check_event_for_spam callback, i just saw that no membership event is going through this callback.
I saw that in multiples servers. My servers using multiples workers/loadbalencing.
Is that normal ?

I know that user_may_invite/join exist but in my case i also need to get the leave event for exemple.

### Steps to reproduce

-Send invite, leave or join event into a room

### Homeserver

unfederated homeserver

### Synapse Version

{"server_version":"1.97.0"}

### Installation Method

pip (from PyPI)

### Database

postgreSQL

### Workers

Multiple workers

### Platform

VM Ubuntu 20.04.6 LTS (GNU/Linux 5.4.0-150-generic x86_64)

### Configuration

_No response_

### Relevant log output

```shell
No log from my check_event_for_spam when membership event.
```

### Anything else that would be useful to know?

_No response_