Fix remaining acceptance tests to be V3-compatible

examples/acceptance_tests/079/validators/foo.ak

@@ -1,9 +1,14 @@
 validator foo {
-  spend(datum: Int, redeemer: Int, _ref: Data, _transaction: Data) {
+  spend(datum: Option<Int>, redeemer: Int, _ref: Data, _transaction: Data) {
+    expect Some(datum) = datum
     datum + redeemer == 42
   }
 
   mint(redeemer: Int, _policy: ByteArray, _transaction: Data) {
     redeemer == 42
   }
+
+  else(_) {
+    fail
+  }
 }