Remove usage of Ptr internal to the library, leave the Ptr function until 4.0

Summary

This change is a code cleanup that replaces a custom helper function called Ptr() with Go's built-in new() keyword throughout the test files. Both do the same thing — they create a pointer to a value — but new() is the standard Go approach and doesn't require a custom utility function.

The update also removes a configuration comment that had been holding back this migration, indicating the work is now complete. No logic or behavior is changed; this is purely a modernization of how pointer values are created in tests.