Remove bogus TODO added in #18585 (#18603)

Removes todo added in #18585 - such normalization is not technically
correct when a tuple is used as a base class.

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Co-authored-by: Ivan Levkivskyi <[email protected]>

Author: sterliakov

mypy/checker.py

@@ -8517,7 +8517,6 @@ def visit_type_var(self, t: TypeVarType) -> bool:
 
     def visit_tuple_type(self, t: TupleType, /) -> bool:
         # Exclude fallback to avoid bogus "need type annotation" errors
-        # TODO: Maybe erase plain tuples used as fallback in TupleType constructor?
         return self.query_types(t.items)