SignalR send to all connections by user ID except one.

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Is your feature request related to a problem? Please describe the problem.

I have a use case for being able to call a SignalR client method for all connections for a given user ID, except the current connection.

### Describe the solution you'd like

I see that the API provides GroupExcept and AllExcept but I didn't find a way to do essentially "UserExcept". Is there a way to do this that I'm simply not finding? Is there a reason that this option wasn't included? The fact that it's missing makes me wonder if there's something wrong with what I'm trying to do, but I can't see how that would be the case.

What I'm doing as a workaround is adding every connection to a group named after their user ID, and then using GroupExcept to do what I need.

Thank you!

### Additional context

_No response_