Cannot request events delta without startDateTime

Describe the bug

Event delta documentation says param startDateTime is optional when working with calendars but class DeltaRequestBuilder always include it in template url causing call to fail with ODataError.

Expected behavior

When performing a normal call without any optional param to get a full delta, no error should append.

How to reproduce

$client->me()
->calendars()
->byCalendarId($remoteId)
->events()
->delta()
->get(
    new DeltaRequestBuilderGetRequestConfiguration([
        'Prefer' => sprintf('outlook.timezone="%s"', $local->getTimeZone()->getName())
    ])
)
->wait()

SDK Version

2.8.0

Latest version known to work for scenario above?

No response

Known Workarounds

No response

Debug output

{
    "error": {
        "code": "ErrorInvalidParameter",
        "message": "The value '' of parameter 'StartDateTime' is invalid."
    }
}

Configuration

No response

Other information

No response

Beginne mit src/Generated/Users/Item/Calendars/Item/Events/Delta/DeltaRequestBuilder.php und vergleiche dessen Template-URL mit der in diesem Issue verlinkten Event-delta-Dokumentation. Reproduziere die Kalender-Delta-Anfrage ohne startDateTime; abgeschlossen ist die Aufgabe, wenn die Anfrage ohne einen ungültigen StartDateTime-Fehler erfolgreich ist, während Anfragen, die den Parameter angeben, weiterhin funktionieren.