Update test for #45060

Equal types should have the same hash, but they are not necessarily
identical.

Update the test to remove the identity check between a constant type and
a type constructed in runtime.

Change-Id: I0d6c6395c587391d3087c26b00fff36d645b33dd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/368340
Reviewed-by: Lasse Nielsen <lrn@google.com>
Commit-Queue: Ömer Ağacan <omersa@google.com>

tests/language/regress/regress45060_test.dart

@@ -34,5 +34,4 @@ class Executor {
 void testTypeEquality<T1, T2>() {
   Expect.equals(T1.hashCode, T2.hashCode);
   Expect.equals(T1, T2);
-  Expect.identical(T1, T2);
 }