change (ci): add interruptible to kubernetes jobs (#6441)

substrate/.gitlab-ci.yml

@@ -56,6 +56,7 @@ default:
     - kubernetes-parity-build
   environment:
     name: parity-build
+  interruptible:                   true
 
 .docker-env:                       &docker-env
   image:                           paritytech/ci-linux:production