std_algos: fix wrong corner case for is_partitioned

[fnrizzi]

Fix wrong behavior for corner case in Kokkos::Experimental::is_partitioned.

Currently, if we were to do:

template <class ValueType>
struct IsNegativeFunctor {
  KOKKOS_INLINE_FUNCTION
  bool operator()(const ValueType val) const { return (val < 0); }
};

Kokkos::View<int*> v = {11, 3, 17, 9, 3};
auto res = KE::is_partitioned(exespace(), KE::cbegin(v), KE::cend(v), p);

we get res == false.
However, this is wrong wrt std library see godbolt here and should return true.
This PR fixes this and the test that was wrongly set to false.

Note that the std library documentation https://en.cppreference.com/w/cpp/algorithm/is_partitioned is not super clear about this, in the sense that when none of the elements satisfy the predicate one could misinterpret it.

Comment: this bug was found when implementing the team-level api in #6256

[dalg24]

OK with the changes but not with the format disable

[dalg24]

The disable format introduces inconsistencies (that look accidental) and it is not obvious to me what benefit we get from disabling.

[cz4rs]

Looks good to me.

[Rombur]

Retest this please