fix: use protocPlugins "none" default

action.yml

@@ -12,7 +12,7 @@ inputs:
     required: false
   protocPlugins:
     description: The protoc language plugins to install, space separated. See README for supported plugins.
-    default: " "
+    default: "none"
     required: false
 
 runs:

scripts/install-buf.sh

@@ -5,17 +5,19 @@ source scripts/executor-info.sh
 
 BUF_VERSION=$1
 
-IFS=" " read -r -a PROTOC_PLUGINS <<< "$2"
-for part in "${PROTOC_PLUGINS[@]}"; do
-  IFS="@" read -r -a langAndVersion <<< "$part"
+if [ "$2" != "none" ]; then
+  IFS=" " read -r -a PROTOC_PLUGINS <<<"$2"
+  for part in "${PROTOC_PLUGINS[@]}"; do
+    IFS="@" read -r -a langAndVersion <<<"$part"
 
-  if [ "${#langAndVersion[@]}" != 2 ]; then
-    echo "Malformed plugin specifier \"$part\", expected e.g. [email protected]"
-    exit 1
-  fi
+    if [ "${#langAndVersion[@]}" != 2 ]; then
+      echo "Malformed plugin specifier \"$part\", expected e.g. [email protected]"
+      exit 1
+    fi
 
-  bash "scripts/install-${langAndVersion[0]}-plugin.sh" "${langAndVersion[1]}"
-done
+    bash "scripts/install-${langAndVersion[0]}-plugin.sh" "${langAndVersion[1]}"
+  done
+fi
 
 if [ ! -f ".bin/buf" ]; then
   echo "Installing buf $BUF_VERSION for OS $UNAME_OS Arch $UNAME_ARCH"