hgext/fastannotate/error.py

typing: add `from __future__ import annotations` to remaining source files

Most of these look newer than when the original imports referenced in the
previous commit were dropped, so these weren't covered by the backout.  These
were found with:

    hg files mercurial hgext hgext3rd -I '**.py' -X '**/thirdparty' \
        | xargs grep -L 'from __future__ import annotations'

All of the `__init__.py` files that finds are empty, so those were ignored and
the rest manually edited.

# Copyright 2016-present Facebook. All Rights Reserved.
#
# error: errors used in fastannotate
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import annotations


class CorruptedFileError(Exception):
    pass


class CannotReuseError(Exception):
    """cannot reuse or update the cache incrementally"""