shelve: trust caller of shelvedfile.opener() to check that the file exists
The only place we call `shelvedfile.opener()` is when we're about to
apply a bundle. The file should always exist. If it doesn't, the
`.hg/` directory is corrupt and we don't provide any guarantees about
supporting corrupt repos (besides, telling the user that the shelve
doesn't exist when `hg shelve --list` lists it is not very helpful).
Differential Revision: https://phab.mercurial-scm.org/D9698
#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