Check extra condition to decide if a test was skipped

It seems that this could happen with PHPUnit 10, then tearDown() would
crash when calling `clear()` on null, but then PHPUnit 10 did not show
that exception.

Author: greg0ire

tests/Tests/OrmFunctionalTestCase.php

@@ -540,7 +540,7 @@ protected function tearDown(): void
         $conn = static::$sharedConn;
 
         // In case test is skipped, tearDown is called, but no setup may have run
-        if (! $conn) {
+        if (! $conn || ! isset($this->_em)) {
             return;
         }