fix: syntax error near unexpected token & (#6458) (#6485)

Co-authored-by: abeizn <zikuan.an@merico.dev>
diff --git a/backend/scripts/build-plugins.sh b/backend/scripts/build-plugins.sh
index 3c31404..da3be3d 100755
--- a/backend/scripts/build-plugins.sh
+++ b/backend/scripts/build-plugins.sh
@@ -36,7 +36,7 @@
 
 
 if [ "$DEVLAKE_PLUGINS" = "none" ]; then
-    echo "skip building plugins" > &2
+    echo "skip building plugins" >&2
     exit 0
 fi