Setting LC_ALL=C makes it possible to use the range `[0-?]` instead of
splitting it into `[0-9:-?]` as done previously. Without LC_ALL, sed
complains with:
sed: -e expression #1, char 21: Invalid range end
The GNU manual explains this partially, although I still don't quite
understand why this range specifically does not work in `en_US.utf8`.
See:
> Within a bracket expression, a *range expression* consists of two
> characters separated by a hyphen. It matches any single character that
> sorts between the two characters, inclusive. In the default C locale,
> the sorting sequence is the native character order; for example,
> `[a-d]` is equivalent to `[abcd]`.
Link: https://www.gnu.org/software/sed/manual/sed.html#Character-Classes-and-Bracket-Expressions
Previously - in the existence of other ANSI escape sequences - the
script deleted text due to the too broad regex. For example in:
foo^[[K bar m
everything behind `foo` was deleted. Thus, only remove SGR sequences by
only matching the spec-allowed bytes.
