Remove `build SHA is outdated for this ref` check for pages builds

As can be seen in https://gitlab.com/gitlab-org/gitlab/pipelines/121633442:

Proposed solution

Add a "smart" check when validating the SHA #208322 (comment 627360109)

 def validate_outdated_sha!
      return if latest?

      if Feature.enabled?(:smart_outdated_pages_check, default_enabled: :yaml)
        deployed_build_id = project.pages_metadatum&.pages_deployment&.ci_build_id

        return unless deployed_build_id
        return if deployed_build_id < build.id
      end

      raise InvalidStateError, 'build SHA is outdated for this ref'
    end