doc: add prerequisites information for Arch

Add prerequisites for Arch Linux and derivatives in BUILDING.md.

PR-URL: #31669
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

BUILDING.md

@@ -244,6 +244,7 @@ Installation via Linux package manager can be achieved with:
 * Fedora: `sudo dnf install python gcc-c++ make`
 * CentOS and RHEL: `sudo yum install python gcc-c++ make`
 * OpenSUSE: `sudo zypper install python gcc-c++ make`
+* Arch Linux, Manjaro: `sudo pacman -S python gcc make`
 
 FreeBSD and OpenBSD users may also need to install `libexecinfo`.