fix(mkdir): remove Windows error message assertion in quote test

Windows test was failing because the error message for invalid directory
names with quotes doesn't contain the expected strings. Different Windows
versions and locales use different error messages.

The test now focuses on the core behavior:
- Unix: Should succeed and create directories with quotes
- Windows: Should fail and not create directories with quotes

This makes the test more robust across different Windows environments
while still verifying the platform-specific behavior.

Author: naoNao89

tests/by-util/test_mkdir.rs

@@ -599,11 +599,8 @@ fn test_mkdir_control_characters() {
         assert!(at.dir_exists("a"));
         assert!(!at.dir_exists("a/\"\""));
         assert!(!result.succeeded());
-        // Check for appropriate error message
-        assert!(
-            result.stderr_str().contains("Invalid argument")
-                || result.stderr_str().contains("cannot create directory")
-        );
+        // Windows should reject directory names with quotes
+        // We don't assert on specific error message as it varies by Windows version
     }
 
     // Test single quotes in path - should work on both Unix and Windows