Fix permissions for jenkins-schema.sh
Fix permissions for jenkins-schema.sh

Jenkins can't execute this file at the moment, so the tests won't run.

https://ci.dev.publishing.service.gov.uk/job/govuk_business_support_find
er_schema_tests/1/console

alphagov/business-support-finder,alphagov/business-support-finder,alphagov/business-support-finder,alphagov/business-support-finder