Use install instead of cp -p to ensure root ownership of sleep hook

cp -p preserves the original user ownership from ~/.local/share/omarchy,
which would allow an unprivileged user to modify a script that runs as
root during suspend/hibernate.

migrations/1773012889.sh

@@ -1,4 +1,4 @@
 echo "Install system-sleep hook to unmount FUSE before suspend/hibernate"
 
 sudo mkdir -p /usr/lib/systemd/system-sleep
-sudo cp -p "$OMARCHY_PATH/default/systemd/system-sleep/unmount-fuse" /usr/lib/systemd/system-sleep/
+sudo install -m 0755 -o root -g root "$OMARCHY_PATH/default/systemd/system-sleep/unmount-fuse" /usr/lib/systemd/system-sleep/