doc: add arm64-musl info into platform list

Signed-off-by: Kleis Auke Wolthuizen <github@kleisauke.nl>

Author: kleisauke

BUILDING.md

@@ -130,6 +130,7 @@ welcome.
 
 | Operating System | Architectures    | Versions[^7]                  | Notes                                |
 | ---------------- | ---------------- | ----------------------------- | ------------------------------------ |
+| GNU/Linux        | arm64            | kernel >= 6.18, musl >= 1.2.5 | e.g. Alpine 3.23                     |
 | GNU/Linux        | x86              | kernel >= 3.10, glibc >= 2.17 | Downgraded as of Node.js 10          |
 | GNU/Linux        | armv7            | kernel >= 4.18, glibc >= 2.28 | Downgraded as of Node.js 24          |
 | GNU/Linux        | loong64          | kernel >= 6.8, glibc >= 2.39  | e.g. Ubuntu 24.04                    |