util: fix width detection for DEL without ICU

This makes sure the DEL character (ASCII 127) is detected as a zero
width character even if Node.js is not built with ICU.

Signed-off-by: Ruben Bridgewater <ruben@bridgewater.de>

PR-URL: https://github.com/nodejs/node/pull/33650


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>