Merge pull request #48052 from nextcloud/backport/48045/stable29

[stable29] fix(dav): set string type for sanitizeMtime

apps/dav/lib/Connector/Sabre/Node.php

@@ -421,7 +421,7 @@ public function getNode(): \OCP\Files\Node {
 		return $this->node;
 	}
 
-	protected function sanitizeMtime($mtimeFromRequest) {
+	protected function sanitizeMtime(string $mtimeFromRequest): int {
 		return MtimeSanitizer::sanitizeMtime($mtimeFromRequest);
 	}
 }