js: deb 11: bump node 19 -> 21

images/debian.dhall

@@ -146,7 +146,7 @@ let
 let
   installNodeJS: CF.Type =
       CF.run "install nodejs"
-      [ "curl -fsSL https://deb.nodesource.com/setup_19.x | sudo -E bash - && sudo apt-get install -y nodejs"
+      [ "curl -fsSL https://deb.nodesource.com/setup_21.x | sudo -E bash - && sudo apt-get install -y nodejs"
       ]
 
 let