[Sema] Update test for previous change

The warning for C++20 extension does not fire in on specific instance
because conversion now fails as class is invalid because of an invalid
member.

The new behavior is expected, so updating the test accordingly

clang/test/SemaCXX/paren-list-agg-init.cpp

@@ -289,7 +289,7 @@ int test() {
   // used to crash
   S a(0, 1);
   S b(0);
-  S c(0, 0, 1); // beforecxx20-warning {{aggregate initialization of type 'S' from a parenthesized list of values is a C++20 extension}}
+  S c(0, 0, 1);
 
   S d {0, 1};
   S e {0};