heptapod-ci: actually give pytest more time before timeout `HGTEST_TIMEOUT` is overridden by `HGTEST_SLOWTIMEOUT` for tests marked as slow, which `test-check-pytype.t` is. So this whole time the timeout was 1500s (or 25 minutes), which is unfortunately not long enough for a *lot* of the times it's run on the CI. Differential Revision: https://phab.mercurial-scm.org/D11717

tests: better determinism in test-chg.t chg tests fail pretty often with "Sample count: *" line disappearing. It disappears because the sample count is zero, in which case a custom message is printed. This commit makes the test succeed in that case. Differential Revision: https://phab.mercurial-scm.org/D11716

hg: remove reserved identifiers Per 7.1.3 paragraph, from C draft: All identifiers that begin with an underscore and either an uppercase letter or another underscore are always reserved for any use.

python: compatibility for python 3.11 (issue6604) The `unittest._TextTestResult` alias has been removed. The "new" name has been available since 3.2, and we only support 3.5.3+. Differential Revision: https://phab.mercurial-scm.org/D11690

pyoxidizer: force pip to not use pep517 in order to be able to install hg Mercurial is not (yet) a pep517 package, but the presence of a pyproject.toml file tells newer-ish versions of pip that it should be one. This is related to 58fe6d127a01, and fixes pyoxidizer builds for the Heptapod CI. Differential Revision: https://phab.mercurial-scm.org/D11710

merge-halt: fix issue with merge.on-failure=halt breaking unshelve Differential Revision: https://phab.mercurial-scm.org/D11706