Remove temp index on License Compliance artifacts

With !38495 (closed) we created a temp artifact that has to be removed as soon as we close #213571 (closed)

Implementation plan

• Create migration that removes the index remove_concurrent_index :ci_job_artifacts, :file_type, where: 'file_type IN (10, 101)'
• No changes anywhere else

Testing

Regression testing should catch any regressions at the unit test, analyzer and Secure Test Projects level.