Rescinded 3pid invites show as errors

@poljar is already working on this.

Since Jul 7, 2026.

Original report in https://github.com/element-hq/element-x-ios/issues/5795

### Steps to reproduce

* Alice sends a 3pid invite to charlie@example.com via EW
* Bob revokes the invite in EW
* Bob sees the following in EX:

### Outcome

#### What did you expect?

No choking on rescinded 3PIDs

#### What happened instead?

It choked on this:

```json
{
"unsigned": {
"replaces_state": "$66JyLdjku41oL48JN1eUM-WfZIgAWeCIisWCNeeo7vY",
"prev_content": {
"display_name": "c...@u...",
"key_validity_url": "https://vector.im/_matrix/identity/v2/pubkey/isvalid",
"public_key": "ta8IQ0u1sp44HVpxYi7dFOdS/bfwDjcy4xLFlfY5KOA",
"public_keys": [
{
"key_validity_url": "https://vector.im/_matrix/identity/api/v1/pubkey/isvalid",
"public_key": "ta8IQ0u1sp44HVpxYi7dFOdS/bfwDjcy4xLFlfY5KOA"
},
{
"key_validity_url": "https://vector.im/_matrix/identity/api/v1/pubkey/ephemeral/isvalid",
"public_key": "MdzMaOKonWpBri_6V8_ZymM6l7qhhc1MuhvgF6F43ms"
}
]
},
"prev_sender": "@raherne:matrix.org",
"age": 742,
"membership": "join"
},
"content": {},
"origin_server_ts": 1782410538742,
"sender": "@matthew:matrix.org",
"state_key": "qzKknoYicpbkGBckNvNqfboCQhCOXHGzUEztJGcKwRneghxNsamUvgHuNkdRsILELNybekRrnoQGWONQxOsEcadXtozixbHcBixfpiYSVerolNEVWIHsENxDlyNPmcST",
"type": "m.room.third_party_invite",
"event_id": "$kUdQvLsBiKYEiUDs_noXUk6w6419U1EXx-aNL44uExg",
"room_id": "!somewhere:matrix.org"
}
```

### Your phone model

macOS

### Operating system version

_No response_

### Application version

1252

### Homeserver

matrix.org

### Will you send logs?

No