modify wallpaper.sh to stop it from letting multiple instances run at the same time

dotfiles/hypr-lap/wallpaper.sh

@@ -1,17 +1,13 @@
 #!/usr/bin/env bash
 
 Wallpaper_DIR="/home/smayzy/wallpaper"
-LOCKFILE="/tmp/wallpaper_changer.lock"
 MONITOR=$(hyprctl monitors | awk '/Monitor/ {print $2; exit}')
 
-if [ -f "$LOCKFILE" ]; then
-    old_pid=$(cat "$LOCKFILE")
-    if ps -p "$old_pid" > /dev/null 2>&1; then
-        kill "$old_pid"
-    fi
-fi
-
-echo $$ > "$LOCKFILE"
+SCRIPT_NAME=$(basename "$0")
+SELF_PID=$$
+pgrep -f "$SCRIPT_NAME" | grep -v "^$SELF_PID$" | while read -r pid; do
+    kill "$pid"
+done
 
 set_wallpaper() {
     local Wallpaper=$(find $Wallpaper_DIR | shuf -n 1)
@@ -25,8 +21,6 @@ set_wallpaper() {
     hyprpaper &
 }
 
-trap "rm -f $LOCKFILE" EXIT
-
 while true; do
     set_wallpaper
     sleep 600