Refactor argument parsing in runtest.sh to improve clarity and consistency

runtest.sh

@@ -8,8 +8,8 @@ NO_ENRICH=0
 LISTENER_ENABLED=0
 LISTENER_ARGS=()
 
-for arg in "$@"; do
-  case $arg in
+while [[ $# -gt 0 ]]; do
+  case "$1" in
     --no-enrich)
       NO_ENRICH=1
       shift
@@ -20,7 +20,7 @@ for arg in "$@"; do
       shift
       ;;
     --listener-channel=*)
-      LISTENER_ARGS+=("--channel" "${arg#*=}")
+      LISTENER_ARGS+=("--channel" "${1#*=}")
       shift
       ;;
     --listener-hop)
@@ -28,7 +28,7 @@ for arg in "$@"; do
       shift
       ;;
     *)
-      echo "Unknown argument: $arg"
+      echo "Unknown argument: $1"
       exit 1
       ;;
   esac