revlog-split: make sure the self._indexfile attribut is reset (issue6811) Before this change, after a transaction committing a file split, a revlog object would have its `self._indexfile` attribute desynchronised from the actual file storing the data. If that same object is reused (as we do for the manifest during clone bundles), this lead to the data being writting in the wrong location and the repository to go corrupt. We not properly reset the attribut when applicable and everything is back in working order.

#require cargo test-repo
  $ . "$TESTDIR/helpers-testrepo.sh"
  $ cd "$TESTDIR"/../rust

Check if Cargo.lock is up-to-date. Will fail with a 101 error code if not.

  $ cargo check --locked --all --quiet

However most CIs will run `cargo build` or similar before running the tests, so we need to check if it was modified

  $ testrepohg diff Cargo.lock