Use security-report-schemas-ruby in gitlab

Why are we doing this work

This finally removes the code that uses the existing json schema files for validation, and replaces it with code that uses the new rubygem.

Relevant links

Non-functional requirements

• Documentation:
  • https://docs.gitlab.com/ee/development/integrations/secure.html#validate-locally
  • https://docs.gitlab.com/ee/development/integrations/secure.html#version
• Feature flag:
• Performance:
• Testing:

Implementation plan

• remove override in ee/lib/ee/gitlab/ci/parsers/security/validators/schema_validator.rb
• update lib/gitlab/ci/parsers/security/validators/schema_validator.rb to use the rubygem for validation
• change the rubygem so that running bundle exec security-report-schemas in the gitlab project, outputs a list of all supported schema versions, marking deprecated ones as such.

Verification steps