Remove `projectFingerprint` from `PipelineSecurityReportFinding` GraphQL

PipelineSecurityReportFinding.projectFingerprint was deprecated in %15.1 via !89578 (merged). This issue covers the removal of the field in %16.0.

See &2791 (comment 790683098)

Proposed deprecation post:

Use uuid instead of projectFingerprint

Implementation plan

1. Delete the project_fingerprint field