[nahapetyan-serob]

closes #1265

[guglielmo-san]

let's add this check before as params.URI might be nil

Suggested change

	server.mu.Lock()
	ids := slices.Clone(server.resourceSubscriptions[params.URI][ss])
	server.mu.Unlock()
	if params == nil {
	return fmt.Errorf("%w: params cannot be nil", jsonrpc2.ErrInvalidParams)
	}
	if params.URI == "" {
	return fmt.Errorf("%w: URI cannot be empty", jsonrpc2.ErrInvalidParams)
	}