branching: merge stable into default

tests: provide an alternate fake lock for filesystems without symlink support

tests: disable `worker.backgroundclose` to stabilize a test on Windows TIL that `worker.enabled=0` doesn't prevent these workers from spinning up. At any rate, there's already a whole lot of conditionalized output following `cat client.log`, the placement of the "starting 4 threads for background file closing" message seems unstable, and we don't care about those worker threads here. Preventing the message is better for test maintenance.

tests: fix lock file path mangling in `test-racy-mutations.t` on Windows I guess `$TESTTMP_FORWARD_SLASH` gets translated by MSYS. This was in the `.foo_commit_out` file: sh: C;C:\\MinGW\\msys\\1.0\\Users\\Matt\\AppData\\Local\\Temp\\hgtests.1qc8jmdl\\child2\\test-racy-mutations.t-skip-detection\\waitlock_editor.sh: $ENOENT

tests: stabilize `test-status-eacces.t` on Windows As noted earlier, `chmod` doesn't complain in MSYS, but also doesn't alter the file permissions such that they are unreadable. I'm guessing the other lines of output in this area that are gated on `rhg` (or not) will also need this, but I don't want to dig too deeply into something that is apparently working well enough.

run-tests: bump the default timeout on Windows to 4x the normal value There are a ridiculous number of tests that timeout on Windows with the 360 sec default (~60). And because of the bug where timed out tests still run to completion before the results are thrown away[1], the timeout does nothing but waste time, so there's no reason to try to find a lower value that still works. For reference on my system: # Ran 909 tests, 116 skipped, 119 failed. python hash seed: 2052473208 real 151m44.322s user 0m0.077s sys 0m0.046s [1] I thought that I wrote a bug for this, but search isn't finding it.

run-tests: bump the minimum python to 3.8 Presumably this was an oversight when hg was updated to 3.8.