.gitlab/merge_request_templates/Default.md

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.

/assign_reviewer @mercurial.review


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