fix: duplicate qr_code validation

Signed-off-by: romanetar <roman_ag@hotmail.com>

Author: romanetar

app/Http/Controllers/Apis/Protected/Summit/OAuth2SummitBadgeScanApiController.php

@@ -95,7 +95,6 @@ function getAddValidationRules(array $payload): array
         return [
             'qr_code'   => 'required_without:attendee_email|string',
             'attendee_email'   => 'required_without:qr_code|email',
-            'qr_code'   => 'required|string',
             'sponsor_id' => 'sometimes|integer',
             'scan_date' => 'required|date_format:U|epoch_seconds',
             'notes' => 'sometimes|string|max:1024',