Overview
This pull request fixes the CurrentDir function in the testutils package.
Previously, runtime.Caller(1) was incorrectly used and the ok return value was ignored, potentially causing unexpected behavior or panics.
The function now uses runtime.Caller(0) to correctly refer to its own file and includes proper error handling if the runtime information is unavailable.

Additional Information

• This fix ensures that CurrentDir() reliably returns the directory of the file where it is defined.
• It improves code robustness and avoids silent failures by explicitly panicking on runtime errors.

How to Test

1. Create a small Go file that calls testutils.CurrentDir().
2. Print the output and verify that it correctly matches the directory path of the testutils package.
3. Optionally, simulate an environment where runtime.Caller could fail (rare but possible in very restricted environments).

Checklist before requesting a review

• My code follows the style guidelines of this project
• I have commented on my code, particularly in hard-to-understand areas
• I have performed a self-review of my code
• If it is a core feature, I have added thorough tests.
• New and existing unit tests pass locally with my changes