Install broadcom-wl-dkms now that Arch dropped the prebuilt module

Arch removed the prebuilt broadcom-wl package on 2026-09-02 and rebuilt
broadcom-wl-dkms with replaces=(broadcom-wl). A replaces entry only helps
upgrades of an already-installed package, so the name is now unresolvable
as an explicit pacman target and the ISO offline mirror download fails
with "target not found: broadcom-wl".

broadcom-wl-dkms depends on dkms, so the explicit dkms in the hardware fix
is redundant; linux-headers stays because the module has to build against
the running kernel.

(cherry picked from commit 649c0b7433)

install/omarchy-other.packages

@@ -5,7 +5,7 @@ autoconf-archive
 asusctl
 base
 base-devel
-broadcom-wl
+broadcom-wl-dkms
 btrfs-progs
 dkms
 egl-wayland