workingfilectx: add backgroundclose as a kwarg to write()
This is necessary because some callers in merge.py pass backgroundclose=True
when writing.
As with previous changes in this series, this should be a no-op.
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true