Adjust the testNarrowingOptionalEqualsNone test case.

A recent change that I just merged seems to interact positively with this PR: increase in consistency when narrowing away `None`.

Author: tyralla

test-data/unit/check-narrowing.test

@@ -1375,9 +1375,9 @@ else:
 if val in (None,):
     reveal_type(val)  # N: Revealed type is "Union[__main__.A, None]"
 else:
-    reveal_type(val)  # N: Revealed type is "Union[__main__.A, None]"
+    reveal_type(val)  # N: Revealed type is "__main__.A"
 if val not in (None,):
-    reveal_type(val)  # N: Revealed type is "Union[__main__.A, None]"
+    reveal_type(val)  # N: Revealed type is "__main__.A"
 else:
     reveal_type(val)  # N: Revealed type is "Union[__main__.A, None]"
 [builtins fixtures/primitives.pyi]