Update websocket.md (#1702)

Removes section on camera_thumbnail and media_player_thumbnail, they were removed in this PR: home-assistant/core#75452

Author: pharris2411

docs/api/websocket.md

@@ -461,66 +461,6 @@ The server will respond with a result message containing the current registered
 }
 ```
 
-## Fetching camera thumbnails
-
-_Introduced in Home Assistant 0.69._
-
-:::caution Deprecated
-This websocket command was depreciated in Home Assistant Core [0.107](https://www.home-assistant.io/blog/2020/03/18/release-107/) and will be removed in a future release. Until then it will result in a `WARNING` entry in the user's log.
-:::
-
-Return a b64 encoded thumbnail of a camera entity.
-
-```json
-{
-  "id": 19,
-  "type": "camera_thumbnail",
-  "entity_id": "camera.driveway"
-}
-```
-
-The server will respond with a result message containing the thumbnail.
-
-```json
-{
-  "id": 19,
-  "type": "result",
-  "success": true,
-  "result": {
-    "content_type": "image/jpeg",
-    "content": "<base64 encoded image>"
-  }
-}
-```
-
-## Fetching media player thumbnails
-
-_Introduced in Home Assistant 0.69._
-
-Fetch a base64 encoded thumbnail picture for a media player.
-
-```json
-{
-  "id": 19,
-  "type": "media_player_thumbnail",
-  "entity_id": "media_player.living_room"
-}
-```
-
-The server will respond with the image encoded via base64.
-
-```json
-{
-  "id": 19,
-  "type": "result",
-  "success": true,
-  "result": {
-    "content_type": "image/jpeg",
-    "content": "<base64 encoded image>"
-  }
-}
-```
-
 ## Pings and Pongs
 
 The API supports receiving a ping from the client and returning a pong. This serves as a heartbeat to ensure the connection is still alive: