fix: issue with tuple clause

It was not consuming the next case if there was no condition being checked in the clause.
Now it properly always consumes the next clause unless last clause.

examples/acceptance_tests/084/lib/tests.ak

@@ -0,0 +1,22 @@
+use aiken/list
+
+test tuple_when() {
+  let items =
+    [(#"", #"", 50), (#"aa", #"bb", 70)]
+
+  let amount = 70
+  let policy = #"aa"
+
+  let filtered =
+    list.filter(
+      items,
+      fn(item) {
+        when item is {
+          (token_policy, _, token_amount) ->
+            amount == token_amount && policy == token_policy
+          _ -> False
+        }
+      },
+    )
+  list.length(filtered) > 0
+}