Messages not always sent in order

### Steps to reproduce

1. Be somewhere with spotty internet (low bandwidth, high packet loss, intermittent disconnects)
2. Send a large attachment (e.g. 5 MB photo) to a room
3. Send a text message to the same room

### Outcome

#### What did you expect?

I expected the messages to remain in the order in which I sent them: The timeline should contain first the photo and then the text message.

#### What happened instead?

The messages got shuffled around. Once connectivity allowed it, the text message was delivered first and (much later) the photo.

### Notes

The symptoms are essentially the same as #1881. Since the root cause of that was apparently fixed though, something else must be going on.

### Your phone model

_No response_

### Operating system version

_No response_

### Application version and app store

Element X v26.04.4 (F-Droid)

### Homeserver

matrix.org

### Will you send logs?

No

### Are you willing to provide a PR?

No