Verification fallbacks get displayed in chat

### Steps to reproduce

Start key verification with an account.

### Outcome

#### What did you expect?

Verification fallbacks don't get shown in the chay

#### What happened instead?

```json
{
"content": {
"body": "@famfo:ccc.ac is requesting to verify your key, but your client does not support in-chat key verification. You will need to use legacy key verification to verify keys.",
"from_device": "meowmeowmeow",
"methods": [
"m.sas.v1"
],
"msgtype": "m.key.verification.request",
"to": "@user:example.com"
},
"event_id": "$1aCz7auGMLUDBRTn_4e4nAiuC8f1Lz2GXCO0w4EWvDY",
"origin_server_ts": 1760811489736,
"room_id": "!<>",
"sender": "@famfo:ccc.ac",
"type": "m.room.message",
"unsigned": {
"age": 31,
"membership": "join",
"transaction_id": "00b2029073904e28af6dd96b81e93c9e"
}
}
```

The content body of that event gets displayed in the chat.

### Your phone model

_No response_

### Operating system version

_No response_

### Application version and app store

25.09.2

### Homeserver

_No response_

### Will you send logs?

Yes

### Are you willing to provide a PR?

No

Reproduce the issue in Element X Android 25.09.2 by starting key verification with an account. Trace how the m.key.verification.request event and its content body are rendered in chat, then verify that verification fallback text is no longer displayed as a regular message.

Written by the indexing model from the issue text.