Make usage of `ChainMap` mypy ready
Currently mypy expects all dicts here to be mutable which is a bug that
will eventually be solved.  But the *first* dict must really be mutable.
So we prepare for that and wait for the "unused ignore" notice from a
future mypy.
@@ -163,7 +163,7 @@ def highlight_linter_errors(views, filename, linter_name):
idle=vid in State['idle_views']
)
squiggle_regions = ChainMap(
- highlight_regions, hidden_highlight_regions # type: ignore[arg-type]
+ {}, highlight_regions, hidden_highlight_regions # type: ignore[arg-type]
) # type: Squiggles
draw(
view,
