Add schemas for existing JSONB columns

Problem

Existing jsonb columns living in GitLab does not have a proper json schema.

Here the exhausting list we should fix forward in spec/db/schema_spec.rb:

  IGNORED_JSONB_COLUMNS = {
    "ApplicationSetting" => %w[repository_storages_weighted],
    "AlertManagement::Alert" => %w[payload],
    "Ci::BuildMetadata" => %w[config_options config_variables],
    "Geo::Event" => %w[payload],
    "GeoNodeStatus" => %w[status],
    "Operations::FeatureFlagScope" => %w[strategies],
    "Operations::FeatureFlags::Strategy" => %w[parameters],
    "Packages::Composer::Metadatum" => %w[composer_json],
    "Releases::Evidence" => %w[summary]
  }.freeze

Proposal

We need to use our new json_schema validator for the following models ☝️

Here an example MR adding json schema validation.

See more on about it in the documentation.