test: improve FileHandler tests portability on root and Windows

Author: gr8man

tests/_support/Session/FileHandlerCloseFail.php

@@ -25,6 +25,8 @@ final class FileHandlerCloseFail extends FileHandler
 {
     public function close(): bool
     {
+        parent::close();
+
         return false;
     }
 }

tests/system/Session/Handlers/FileHandlerTest.php

@@ -241,6 +241,10 @@ public function testOpenThrowsForWriteProtectedSavePath(): void
         mkdir($dir, 0700);
         chmod($dir, 0555);
 
+        if (is_writable($dir)) {
+            $this->markTestSkipped('Directory permissions cannot be restricted for this user (e.g. running as root).');
+        }
+
         try {
             $handler = $this->getInstance();
 
@@ -533,6 +537,10 @@ public function testGCWhenDirectoryCannotBeOpened(): void
         mkdir($dir, 0700);
         chmod($dir, 0000);
 
+        if (@opendir($dir) !== false) {
+            $this->markTestSkipped('Directory permissions cannot be restricted for this user (e.g. running as root).');
+        }
+
         try {
             $handler = $this->getInstance(['savePath' => $dir]);