pam/gdmmodel-test: Do not use sub-sequences to send ordered commands

As per a bubbletea issue sub-sequences of messages may not preserve the
order, so let's just handle them by appending the messages to the
commands we already have instead, so that there's no risk that the order
is not preserved and that the subsequence is executed when all the
remaining commands also are

See: charmbracelet/bubbletea#847

pam/internal/adapter/gdmmodel_uimodel_test.go

@@ -127,15 +127,18 @@ func (m *gdmTestUIModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		}()
 
 	case *gdmTestWaitForStageDone:
-		msgCommands := tea.Sequence(msg.commands...)
+		// FIXME: We can't just define msgCommands a sub-sequence as we used to
+		// do since that's unreliable, as per a bubbletea bug:
+		//  - https://github.com/charmbracelet/bubbletea/issues/847
+		msgCommands := slices.Clone(msg.commands)
 		if len(msg.events) > 0 {
 			m.gdmHandler.appendPollResultEvents(msg.events...)
 			// If we've events as poll results, let's wait for a polling cycle to complete
-			msgCommands = tea.Sequence(tea.Tick(gdmPollFrequency, func(t time.Time) tea.Msg {
+			msgCommands = append([]tea.Cmd{tea.Tick(gdmPollFrequency, func(t time.Time) tea.Msg {
 				return nil
-			}), msgCommands)
+			})}, msgCommands...)
 		}
-		commands = append(commands, msgCommands)
+		commands = append(commands, msgCommands...)
 
 	case gdmTestSendAuthDataWhenReady:
 		doneMsg := gdmTestWaitForCommandsDone{seq: gdmTestSequentialMessages.Add(1)}