Fix logging in import runner

[kunalsz]

In reference to the issue #1477

Changes made:

• In import_runner.py the logging message has been changed from

except ValidationError as e:
        logger.warning(f"Invalid vulnerability reference: {reference!r}: {e}")

to

except ValidationError as e:
        error_message = str(e)
        if "Vulnerability reference with this Url already exists." in error_message:
            logger.debug(f"Duplicate vulnerability reference ignored: {reference!r}")
        else:
            logger.warning(f"Invalid vulnerability reference: {reference!r}: {e}")

• This ensures that

  • Duplicate reference messages no longer appear as warnings but be logged in debug mode logger.debug
  • Other validation errors should still be logged as warnings

• Tests created to ensure proper logging of error messages