Log Message:
Update Mercurial to 6.7.4:
    inline-changelog: fix a critical bug in write_pending that delete data \ 
(3cf9e52f5e27)
    inline-changelog: fix pending transaction visibility when splitting \ 
(1721d983dd6d)

    exchange: fix locking to actually be scoped
    chistedit: change action for the correct item
    rust-status: sort the failed matches when printing them
    hooks: add a prewlock and a prelock hooks
    bookmark: fix remote bookmark deletion when the push is raced