windows-ci: temporarily allow Windows jobs to fail
We have unfortunately ran out of free credit on the runners we were using from
OVH for the Windows CI. We will be disabling the two remaining ones on the 30th
of September, hence we need the CI to pass even if Windows jobs cannot start as
a temporary measure. Hopefully we can find another way of getting Windows
runners soon.
Differential Revision: https://phab.mercurial-scm.org/D11499
Our full contribution guidelines are in our wiki, please see:
https://www.mercurial-scm.org/wiki/ContributingChanges
If you just want a checklist to follow, you can go straight to
https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist
If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).