Update issues numbers for builtins.function (#12580)

Author: srittau

stdlib/builtins.pyi

@@ -968,7 +968,9 @@ class tuple(Sequence[_T_co]):
     if sys.version_info >= (3, 9):
         def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
 
-# Doesn't exist at runtime, but deleting this breaks mypy. See #2999
+# Doesn't exist at runtime, but deleting this breaks mypy and pyright. See:
+# https://github.com/python/typeshed/issues/7580
+# https://github.com/python/mypy/issues/8240
 @final
 @type_check_only
 class function: