Both promote-to-uat and promote-prod workflows now delete any
existing completed Jobs with the same short SHA suffix before Flux
reconciles. This prevents the immutable-podTemplate error that was
blocking UAT at image tag a67e541:
Job.batch "migrate-schema-xxx" is invalid: spec.template: field is immutable
Also added missing failure notification step to promote-prod workflow.
Co-Authored-By: Paperclip <noreply@paperclip.ing>