[BUGFIX] Fix undefined index in ContentObjectRenderer

Like the surrounding $conf['max'], this array index access should also
be secured.

Releases: main, 11.5
Resolves: #97908
Change-Id: I36ad5cf3d9eac5655e8721c8913bed43ab26377f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75134
Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>

typo3/sysext/frontend/Classes/ContentObject/ContentObjectRenderer.php

@@ -6046,7 +6046,7 @@ public function getQuery($table, $conf, $returnQueryArray = false)
         $error = false;
         if (($conf['max'] ?? false) || ($conf['begin'] ?? false)) {
             // Finding the total number of records, if used:
-            if (str_contains(strtolower(($conf['begin'] ?? '') . $conf['max']), 'total')) {
+            if (str_contains(strtolower(($conf['begin'] ?? '') . ($conf['max'] ?? '')), 'total')) {
                 $countQueryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)->getQueryBuilderForTable($table);
                 $countQueryBuilder->getRestrictions()->removeAll();
                 $countQueryBuilder->count('*')