build: use LC_ALL of C for maximum compatibility

LC_ALL=en_US breaks on some systems (notably the SmartOS 16
configuration in our CI). Use LC_ALL=C instead.

PR-URL: https://github.com/nodejs/node/pull/21222


Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>