Add GoogleCloudPlatform::WorkloadIdentityFederation integration

db/docs/integrations.yml

doc/api/integrations.md

ee/app/controllers/concerns/ee/integrations/params.rb

ee/app/models/ee/group.rb

ee/app/models/ee/integration.rb

ee/app/models/ee/project.rb

...ons/google_cloud_platform/workload_identity_federation.rb

..._flags/beta/google_cloud_workload_identity_federation.yml

ee/lib/ee/api/helpers/integrations_helpers.rb

ee/spec/factories/integrations.rb

...tform/user_activates_workload_identity_federation_spec.rb

...tform/user_activates_workload_identity_federation_spec.rb

ee/spec/models/ee/group_spec.rb

ee/spec/models/ee/integration_spec.rb

ee/spec/models/ee/project_spec.rb

...oogle_cloud_platform/workload_identity_federation_spec.rb

ee/spec/requests/api/integrations_spec.rb

locale/gitlab.pot

spec/lib/gitlab/import_export/all_models.yml