test(admin): cover orphan resync status cleanup

[overtrue]

Related Issues

N/A

Summary of Changes

This adds focused regression coverage for site replication remove state cleanup.

Recent remove-site logic now prunes resync_status entries whose deployment IDs no longer exist in peers, even when the requested site name does not match any current peer. Without a dedicated test, that orphan-status cleanup path could regress while the removed-peer and local-site removal tests still pass.

The new unit test builds a state with two active peers plus one orphaned resync status, calls remove_sites with a missing site name, and verifies active peer state remains intact while the orphaned resync status is removed.

Verification

• cargo test -p rustfs test_remove_sites_prunes_orphan_resync_status_without_matching_site
• cargo fmt --all
• cargo fmt --all --check
• make pre-commit

Impact

No user-facing behavior change. This is test-only coverage for existing site replication cleanup behavior.

Additional Notes

N/A

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Pull request overview

Adds a targeted regression test in the admin site-replication handler to ensure remove_sites continues to prune orphaned resync_status entries even when the requested site name does not match any current peer.

Changes:

• Introduces a unit test that constructs a state with valid peers plus an orphaned resync_status entry.
• Verifies remove_sites leaves active peer state intact while dropping the orphaned resync_status entry when called with a non-existent site name.