Added missing getMicrosecond to DateTimeInterface

Author: marc-mabe

ext/date/php_date.stub.php

@@ -325,6 +325,8 @@ public function getOffset(): int;
     /** @tentative-return-type */
     public function getTimestamp(): int;
 
+    public function getMicrosecond(): int;
+
     /** @tentative-return-type */
     public function diff(DateTimeInterface $targetObject, bool $absolute = false): DateInterval;