Use consistent bash5 style for conditionals and quoting

bin/omarchy-battery-monitor

@@ -11,8 +11,8 @@ send_notification() {
   notify-send -u critical "󱐋 Time to recharge!" "Battery is down to ${1}%" -i battery-caution -t 30000
 }
 
-if [[ -n "$BATTERY_LEVEL" && "$BATTERY_LEVEL" =~ ^[0-9]+$ ]]; then
-  if [[ $BATTERY_STATE == "discharging" && $BATTERY_LEVEL -le $BATTERY_THRESHOLD ]]; then
+if [[ -n $BATTERY_LEVEL && $BATTERY_LEVEL =~ ^[0-9]+$ ]]; then
+  if [[ $BATTERY_STATE == "discharging" ]] && (( BATTERY_LEVEL <= BATTERY_THRESHOLD )); then
     if [[ ! -f $NOTIFICATION_FLAG ]]; then
       send_notification $BATTERY_LEVEL
       touch $NOTIFICATION_FLAG