Update btrfs-backup script. Add lock file generation

nixos/common/software/cli/scripts/btrfs-backup.sh

@@ -37,7 +37,7 @@ LOCK_FILE="/var/run/btrfs-backup-${1}.lock"
 
 # Lock file creation with cleanup
 cleanup_lock() {
-    rm -f "$LOCK_FILE"
+    sudo rm -f "$LOCK_FILE"
 }
 
 create_lock() {
@@ -48,7 +48,7 @@ create_lock() {
             exit 1
         else
             # Lock file exists but process is not running, remove stale lock
-            rm -f "$LOCK_FILE"
+            cleanup_lock
         fi
     fi