Remove disk-clean workflow (#30741)

The jobs in the workflow runs in parallel. The `disk-clean` job actually
does nothing, i.e. it will not clean the disk for `nightly-binary`,
`nightly-docker-rootful`, `nightly-docker-rootless`

Author: harryzcy

.github/workflows/disk-clean.yml

@@ -9,8 +9,6 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  disk-clean:
-    uses: ./.github/workflows/disk-clean.yml
   nightly-binary:
     runs-on: nscloud
     steps: