ci: only use the macOS runner if manually invoked Right now, we only have a single machine with a single runner, so don't create a bottleneck by default.

ci: add a runner for macos This is running from a venv, created with the packages from the requirements file in the `test-setup-future-work` topic being discussed separately. We can basically reuse the existing `test_c` configuration as-is, but there was one small issue- if the clone from the previous CI run is still present in `/tmp`, the clone for the current run fails. It's not a problem for the current setup because a new container is instantiated, so the easy fix is to simply delete the clone first. (The Windows CI avoids this by not cloning in the first place.) It looks like it takes ~80m to run the whole test suite on the current system.

branching: merge stable into default

tests: use shlex.quote instead of pipes.quote The pipes module got removed in python 3.13. https://bugs.debian.org/1084553

branchmap-v3: make sure we write the cache after detecting pure-topo mode We were properly detecting the pure topo-case but in some case the one disk cache file was never updated with that information.

demande-import-test: use `wsgiref` instead of `telnetlib` for testing The `telnetlib` module has been dropped in 3.13. The `wsgiref` module fit the same purpose of being obscure and not imported yet.

hgdemandimport: add collections.abc to the ignore list because Python 3.13 rc3 It worked in Python 3.13 rc2, but something changed for rc3. Now, when i18n.py imports typing and it touches collections.abc.Hashable , we get: ValueError: module object for collections.abc substituted in sys.modules during a lazy load This seems to be a general problem, released in the final Python 3.13 . I have not analyzed the problem in details. We *could* work around the problem by disabling demand import of typing. But that would effectively disable demand import of collections.abc too. Instead, just disable demand import for collections.abc .