Checksum Test for ::Vulnerabilities::CreateService and ::Vulnerabilities::FindOrCreateFromSecurityFindingService

#387665 (comment 1255907700)

Due to the implementation of these services in !97699 (merged) and !107367 (merged) due to the high complexity of re-implementing them in the service of those migrations, there is now a risk of breaking the GitLab upgrade path by modifying these services.

As such, we should implement some kind of safeguard against changing them without due consideration, as this is the kind of possible issue which is likely to be forgotten about or not known about by new developers in future work.

Implementation Plan

• Implement a CI test which generates a MD5 or SHA hash of the files for ::Vulnerabilities::CreateService and ::Vulnerabilities::FindOrCreateFromSecurityFindingService and compares them to known outputs. If they change, the pipeline should fail with a link to this issue explaining the risks associated with their change.