Log Message:
py-mercurial: update to 6.1.3.

Mercurial 6.1.3

security:

    narrow_widen_acl: enforce narrowacl in narrow_widen (SEC) 6b10151b9621

normal notes:

    censor: fix [hg update] away from a revision with censored files
    amend: stop losing copies when amending
    rhg: strengthen dirstate v2 writing in broken filesystems
    work around some broken DLL imports in Windows
    worker: adapt _blockingreader to work around a python3.8.[0-1] bug (issue6444)
    rhg: correctly handle the case where diffs are encoded relative to nullrev
    fix bugs and race-conditions in the Mercurial test runner
    chg: ignore already closed fds when cleaning up