fsmonitor: migrate Python ABCs from collections to collections.abc
The Collections Abstract Base Classes in the collections module are
deprecated since Python 3.3 in favor of collections.abc, and removed
in Python 3.10.
= Mercurial XXX =
== New Features ==
== Default Format Change ==
These changes affect newly created repositories (or new clones) done with
Mercurial XXX.
== New Experimental Features ==
== Bug Fixes ==
== Backwards Compatibility Changes ==
* chg worker processes will now correctly load per-repository configuration
when given a both a relative `--repository` path and an alternate working
directory via `--cwd`. A side-effect of this change is that these workers
will now return an error if hg cannot find the current working directory,
even when a different directory is specified via `--cwd`.
== Internal API Changes ==
== Miscellaneous ==