legacyCompat.redis_decode(s: string): string
LANraragi::Utils::Redis::redis_decode — legacy re-decodes a value read back from Redis
as UTF-8, since Perl's own Redis client hands back raw bytes. Deno's Redis client (and
every string this dispatcher otherwise touches) is already a proper UTF-8 JS string by the
time a plugin sees it, so this is a pure pass-through.