Build dropbox and dropbox-cli for aarch64

Dropbox publishes its Linux client for x86_64 only, so on AArch64 the
dropbox package installs that same client and runs it under box64. Only
dropboxd changes: it execs the client through box64, and /usr/bin/dropbox
points at it, so the systemd units and `dropbox-cli start` both go through
the emulator. The x86_64 package is unchanged.

dropbox-cli is a Python script and becomes arch=any.

pkgbuilds/dropbox-cli/PKGBUILD

@@ -7,9 +7,9 @@
 
 pkgname=dropbox-cli
 pkgver=2026.09.28
-pkgrel=1
+pkgrel=2
 pkgdesc="Command line interface for Dropbox"
-arch=("x86_64")
+arch=("any")
 url="https://www.dropbox.com"
 license=("GPL-3.0-or-later")
 makedepends=("gdk-pixbuf2")