SNOW-1460707: Fix permission error when there is no permission on the parent directory of config file path

[sfc-gh-jdu]

Please answer these questions before submitting your pull requests. Thanks!

1. What GitHub issue is this PR addressing? Make sure that there is an accompanying issue to your PR.

   Fixes SNOW-1460707: Erroneously Looking for Config.toml File when using DATABASES dictionary in settings.py #1959

2. Fill out the following pre-review checklist:

   • I am adding a new automated test(s) to verify correctness of my new code
   • I am adding new logging messages
   • I am adding a new telemetry message
   • I am modifying authorization mechanisms
   • I am adding new credentials
   • I am modifying OCSP code
   • I am adding a new dependency

3. Please describe how your code solves the related issue.

   path.exists will raise a PermissionError if there is no permission on the parent directory of config file path

[sfc-gh-mkeller]

Why did you add a debug log for failing to read a configuration file.
I do not think that's an appropriate logging level for such a case.