It's not quite clear why I added this originally. ripgrep doesn't have
its `-a` flag enabled. It's possible I tricked myself into adding it
because ripgrep's binary detection has evolved to be more like GNU
grep's nowadays.
In any case, using `-a` on data that is non-binary can only improve
performance because it removes the overhead for checking whether the
data is binary or not. So this was giving an artificial boost to GNU
grep.
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