Merge pull request #47867 from nextcloud/backport/47858/stable29

[stable29] fix(preview): gracefully handle file not being opened in ProviderV2

Author: skjnldsv

lib/private/Preview/ProviderV2.php

@@ -88,6 +88,9 @@ protected function getLocalFile(File $file, ?int $maxSize = null) {
 			$absPath = \OC::$server->getTempManager()->getTemporaryFile();
 
 			$content = $file->fopen('r');
+			if ($content === false) {
+				return false;
+			}
 
 			if ($maxSize) {
 				$content = stream_get_contents($content, $maxSize);