tests/test-dirstate-backup.t

tests: remove hg10 requirement from test-check-pylint.t

Since pylint does its own directory traversal to find files to check and
doesn't use hg locate command, this requirement is not valid.

See also a29f071751df.

Set up

  $ hg init repo
  $ cd repo

Try to import an empty patch

  $ hg import --no-commit - <<EOF
  > EOF
  applying patch from stdin
  abort: stdin: no diffs found
  [10]

No dirstate backups are left behind

  $ ls .hg/dirstate* | sort
  .hg/dirstate