.editorconfig

tests: update test-util.py for modern attrs package

When updating to 22.1.0, this test started failing:

    Traceback (most recent call last):
      File "/tmp/mercurial-ci/tests/test-util.py", line 53, in <module>
        _start_default = (util.timedcmstats.start.default, 'factory')
    AttributeError: type object 'timedcmstats' has no attribute 'start'

Poking around in `hg debugshell`, the attribute is indeed missing, but looks to
be attached to `__attrs_attrs__` in both the currently vendored and the modern
version of attrs.  The old attrs packages will print the same for both accesses,
so fingers crossed...

    >>> print((util.timedcmstats.start.default, 'factory'))
    (Factory(factory=<function timedcmstats.<lambda> at 0x000001EFDF0F21F0>, takes_self=False), 'factory')

    >>> print((util.timedcmstats.__attrs_attrs__.start.default, 'factory'))
    (Factory(factory=<function timedcmstats.<lambda> at 0x000001EFDF0F21F0>, takes_self=False), 'factory')

# See http://EditorConfig.org for the specification

root = true

[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
end_of_line = lf

[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true
end_of_line = lf

[*.t]
indent_size = 2
indent_style = space
trim_trailing_whitespace = false
end_of_line = lf