Avoid Deprecation warning from Zip tests on PHP 8.1

It is not allowed anymore to open an empty file as a new zip archive.

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

tests/lib/Archive/ZIPTest.php

@@ -17,6 +17,6 @@ protected function getExisting() {
 	}
 
 	protected function getNew() {
-		return new ZIP(\OC::$server->getTempManager()->getTemporaryFile('.zip'));
+		return new ZIP(\OC::$server->getTempManager()->getTempBaseDir().'/newArchive.zip');
 	}
 }