Apply suggestions from code review

Co-authored-by: Marcel Klehr <mklehr@gmx.net>
Signed-off-by: janepie <49834966+janepie@users.noreply.github.com>
Signed-off-by: Jana Peper <jana.peper@nextcloud.com>

Author: janepie

lib/BackgroundJob/RegenerateOutdatedChatSummariesJob.php

@@ -20,7 +20,7 @@ public function __construct(
 		private SessionSummaryService $sessionSummaryService,
 	) {
 		parent::__construct($timeFactory);
-		$this->setInterval(60 * 10); // 10min
+		$this->setInterval(60 * 60); // 1h
 	}
 	public function run($argument) {
 		$userId = $argument['userId'];

lib/Service/SessionSummaryService.php

@@ -110,7 +110,7 @@ public function getUserSessionSummaries(?string $userId): array {
 
 	/**
 	 * returns all remembered chats as summaries where available and whole chats where not
-	 * @return array<string>
+	 * @return list<string|null>
 	 */
 	public function getMemories(?string $userId): array {
 		$memories = [];