Issue #3621587: Catch yoyaku up with current orchestra, and with what Drupal 11.5 deprecated

Orchestra removed two methods the test suite calls, so the suite fails against current orchestra even where yoyaku is unchanged. No production code called either.

InteractionToken::isValid() was deleted in orchestra 2876c950 (#3620614) as dead code, orchestra having no caller of its own. It was a one-line convenience over open(), which survives:

public function isValid(int $instance_id, string $provided): bool {
  return $this->open($provided)?->instanceId === $instance_id;
}

The two kernel tests now ask what it asked. Asked as the instance rather than as a boolean, so a failure names the instance the token carried instead of only saying false.

OrchestraNotificationEvent::getProcessInstanceAttachments() became getAttachments() in orchestra 470ea04c (#3620621); the ticket test follows.

What this clears, and what it does not

This is the whole static half of the drift: phpstan now reports no errors, where it reported exactly these five calls. The three affected classes pass locally - TicketNotificationSubscriberTest (3 tests), CalendarInteractionSubscriberTest (1), CheckoutResumeSubscriberTest (4) - and phpcs and cspell are clean.

It does not fix the four scenario failures in BookingWorkflowE2eTest (n_cancel_window_operator and n_attendance absent from the parked nodes, and a NULL work item). Those are a behavioural drift, not a missing method, so the functional job stays red until they are resolved. They are still being traced and will not be guessed at here.

AI-Generated: Yes (Claude Code was used to help draft this merge request and to write the fix. I reviewed it and ran the three affected test classes before posting.)