When mentioning a room's own alias in the room, it sends unintended room ping (similar to old @room behavior)

[aine-etke]

Describe the bug

When in a room with alias #some-room:example.com you add that alias into the message, it pings all users within the room somehow

Reproduction

1. Create a room
2. Assign an alias to that room (example: #some-room:example.com)
3. Send a message in that room that will have #some-room:example.com mentioned somewhere in the text
4. Wake up everyone in that room, similarly to @room

Expected behavior

Mentioning of the room's own alias should not result into room mention (@room-like notification for all room members)

Platform and versions

Cinny v4.10.2

Additional context

That happened in the #mrs:etke.cc room, specific event: https://matrix.to/#/#mrs:etke.cc/$NJVpI4sREce4qtywIWPElyKvAR2Qp5_zlb_vHBi9p1c

Below is shrinked json of the event's content:

{
  "content": {
    "body": "..., #mrs:etke.cc , ...",
    "format": "org.matrix.custom.html",
    "formatted_body": "..., <a href=\"https://matrix.to/#/#mrs:etke.cc\">#Matrix Rooms Search</a> , ...",
    "m.mentions": {
      "room": true,
      "user_ids": [
        "REDACTED_VALID_MXID_TO_WHOM_REPLY_WAS_ADDRESSED"
      ]
    },
    "m.relates_to": {
      "m.in_reply_to": {
        "event_id": "$RuTC0O7jKZuDcZv-ZKyzBqomi8QZe5m4iw6BmEOD08U"
      }
    },
    "msgtype": "m.text"
  },
}

@nexy7574 mentioned they may know more details about the root cause of the issue

[nexy7574]

@nexy7574 mentioned they may know more details about the root cause of the issue

Haven't looked into it beyond a guess however it may be related due to some implementation details of intentional mentions in #2138.