Fix SBOM scan result file cleanup by using created_at timestamp

What does this MR do and why?

Fix SBOM scan result file cleanup by using created_at timestamp

The SbomScanUploader was using Time.current in its path generation, causing result files to become inaccessible after the date changes. This prevented the cleanup worker from deleting expired files.

This change updates the uploader to use the scan's created_at timestamp consistently for path generation, ensuring files can be accessed and deleted at the correct path regardless of when the operation occurs.

References

• SBOM scan result files are not being cleaned up... (#580573)

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