test(tvix/nix-compat/nar/wire): cover TOK_PAD_PAR

Change-Id: Ib4da612a4144d062f55a22b437c725b8566bee70
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12172
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>

tvix/nix-compat/src/nar/wire/mod.rs

@@ -119,6 +119,8 @@ fn tokens() {
         (&TOK_ENT, &["entry", "(", "name"]),
         (&TOK_NOD, &["node", "(", "type"]),
         (&TOK_PAR, &[")"]),
+        #[cfg(feature = "async")]
+        (&TOK_PAD_PAR, &["", ")"]),
     ];
 
     for &(tok, xs) in cases {