git: 0b4a06ab29a0..a3f3a7b4dc80 - vendor/bc - vendor branch updated

From: Stefan Eßer <se_at_FreeBSD.org>
Date: Tue, 02 Jan 2024 13:07:44 UTC
The branch vendor/bc has been updated by se:

URL: https://cgit.FreeBSD.org/src/log/?id=0b4a06ab29a0..a3f3a7b4dc80

a3f3a7b4dc80 vendor/bc: upgrade to version 6.7.4