perf: add historical support of ui.load()
ui.load() has been available since d83ca854 and at the time of writing isn't
available on stable branch breaking benchmarking newer stable revisions.
Add historical portability policy note on contrib/benchmarks
# 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