A MissingError traceback that occurs in `_build_bus_channel_list` was
caught by Sentry. This error has been seen 1.3k times in the last 30
days from several customers.
The fix simply consists in checking if the document exists before
checking the rights on it.
Traceback:
```
MissingError: Record does not exist or has been deleted.
(Record: project.task(83,), User: 6)
File "addons/bus/websocket.py", line 879, in _serve_forever
req.serve_websocket_message(message)
File "addons/bus/websocket.py", line 752, in serve_websocket_message
service_model.retrying(
File "odoo/service/model.py", line 134, in retrying
result = func()
File "addons/bus/websocket.py", line 767, in _serve_ir_websocket
ir_websocket._subscribe(data)
File "addons/bus/models/ir_websocket.py", line 38, in _subscribe
channels = set(self._build_bus_channel_list(data['channels']))
File "home/odoo/src/enterprise/16.0/spreadsheet_edition/models/ir_websocket.py", line 13, in _build_bus_channel_list
return super()._build_bus_channel_list(channels)
File "addons/web_editor/models/ir_websocket.py", line 33, in _build_bus_channel_list
document.check_access_rule('read')
```
SAAS-K22 (sentry code)
opw-3086292
closesodoo/odoo#106982
X-original-commit: 9e4c5e427285b76000398476e9d923e7ea036a65
Signed-off-by: Achraf <abz@odoo.com>