A duplicate transition task admitted after the winner released its
in-flight claim (#4839) re-reads the version before uploading, but on
unversioned buckets that read could hit a stale pre-transition entry in
the 2s-TTL GET metadata cache: transition_object never invalidated the
cache after delete_object_version persisted transition_status=complete
and freed the local data. The stale hit defeated the TRANSITION_COMPLETE
early-return, so the duplicate streamed the already-deleted local data
to the remote tier (NotFound reader errors + rejected duplicate tier
PUT with UnexpectedContent).
Invalidate the cache right after the transitioned metadata is persisted,
matching the other metadata-mutating paths, and add a regression test
that runs a duplicate transition against an already-transitioned version
and asserts no second tier upload and unchanged remote object metadata.
Fixes#4827
Zhengchao An
04bfd48eb1