run-tests: display the time it took to install Mercurial It will help make people aware of this critical step and to assess the time it takes in various options (like a CI run for example).

run-tests: deal with distutil deprecation PEP 632 recommend the use of `packaging.version` to replace the deprecated `distutil.version`. So lets do it.

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.