Refine DevOps deletion

What this PR dose

According to the instruction, I updated the DevOps uninstallation in scripts/kubesphere-delete.sh, especially making all DevOps CRs deletable with three for loops.

Why we need it

Please see https://github.com/kubesphere/website/issues/2155.

/kind optimization /cc @kubesphere/sig-installation /cc @kubesphere/sig-devops