Log Message:
py-mercurial: update to 6.6.

As usual, a *lot* of patches don't make it to this list.

New Features

    rust-config: add support for default config items
    rhg: add config defaults to configitems.toml
    rhg: support "status FILE"
    rhg: support rhg files [FILE]
    commands: add admin namespace
    admin-command: add verify command
    debug-delta-chain: add options to control what we compute
    Added some caching for uncompressed revlog chunks that speed up some operations

New Experimental Features

Bug Fixes

    Improve OpenVMS support
    byteify-strings: passe sysstr to attr function and wrapper
    journal: track bookmark deletion
    transaction: actually delete file created during the transaction on rollback
    pull: avoid referencing a variable before it is initialized
    rust-filepatterns: also normalize RelPath
    narrow: hoist a variable to a higher level to avoid use-before-init warning
    convert: stabilize subversion date sorter
    run-tests: detect HGWITHRUSTEXT value
    censor: accept censored revision during upgrade
    rust-matchers: fix quadratic complexity in FileMatcher
    unstable: do not consider internal phases when computing unstable
    Still a whole bunch of Python 2 -> 3 migration leftovers

Backwards Compatibility Changes

    perf: display all timing by default
    infinitepush: drop the extension
    debug-delta-chain: print less data by default

Internal API Changes

    The revlog interface has been significantly cleaned up.
    configitems: add documentation field
    configitems: declare items in a TOML file
    configitems: move blackbox's config items to the new configitems.toml
    path-suboption: deprecated specifying the attributes as bytes
    pycompat: deprecate using bytes
    check-code: drop the safehasattr rule
    safehasattr: drop usage in favor of hasattr
    rust: add UncheckedRevision type
    rust: implement the Graph trait for all revlogs
    rust: make Revision a newtype
    perf: change the way we approach revlog reading
    perf: ensure all readlog's reading is done within a reading context
    delta-chain: move the debugdeltachain command in revlogutils