Fix code scanning alert no. 59: Overly permissive file permissions

[jordanpadams]

Fixes https://github.com/NASA-PDS/doi-service/security/code-scanning/59

To fix the problem, we need to change the file permissions to be more restrictive, allowing only the owner to read and write the file. This can be achieved by modifying the os.chmod calls to set the file permissions to 0o0600, which grants read and write permissions only to the file owner.

Specifically, we need to update the os.chmod calls on lines 173 and 184 to use 0o0600 instead of 0o0664. This change ensures that the files are not world-readable and are only accessible by the owner.

Suggested fixes powered by Copilot Autofix. Review carefully before merging.

[nutjob4life]

On main, pytest gives:

89 passed, 15 skipped, 151 warnings in 6.73s

On alert-autofix-59, though, pytest gives:

1 failed, 88 passed, 15 skipped, 151 warnings in 7.07s

I think we better just reject this. The test pds_doi_service.core.db.test.transaction_test.TransactionOnDiskTestCase explicitly looks for the file mode and does not like 0600.

[jordanpadams]

Closing as wontfix.