complexity issue in `Iterable.iteratesInAnyOrder`

[DaPutzy]

The Iterable.iteratesInAnyOrder method suffers from a computational complexity issue that severely impacts performance. Although its fast enough on small lists, its execution time becomes noticeably slower with more than 10 entries and grows to prohibitive lengths with approximately 20 entries (>24h).

Note that the issue only occurs with non-matching lists, if the lists are indeed identical execution time is completly within acceptable limits (~20ms for 20 entries).

Example code to reproduce:

import static org.saynotobugs.confidence.Assertion.assertThat;
import static org.saynotobugs.confidence.core.quality.Iterable.iteratesInAnyOrder;

import java.util.List;

import org.junit.jupiter.api.Test;

class FooTest {

	@Test
	void fails_within_reasonable_amount_of_time() {
		assertThat(
			List.of(
				"foo-1",
				"foo-2",
				"foo-3",
				"foo-4",
				"foo-5"
			),
			iteratesInAnyOrder(
				"foo-1",
				"foo-2",
				"foo-3",
				"foo-4",
				"foo-5",
				"foo-6"
			)
		);
	}

	@Test
	void fails_but_already_takes_15sec() {
		assertThat(
			List.of(
				"foo-1",
				"foo-2",
				"foo-3",
				"foo-4",
				"foo-5",
				"foo-6",
				"foo-7",
				"foo-8",
				"foo-9",
				"foo-10",
				"foo-11"
			),
			iteratesInAnyOrder(
				"foo-1",
				"foo-2",
				"foo-3",
				"foo-4",
				"foo-5",
				"foo-6",
				"foo-7",
				"foo-8",
				"foo-9",
				"foo-10",
				"foo-11",
				"foo-12"
			)
		);
	}

	@Test
	void fails_but_takes_3min() {
		assertThat(
			List.of(
				"foo-1",
				"foo-2",
				"foo-3",
				"foo-4",
				"foo-5",
				"foo-6",
				"foo-7",
				"foo-8",
				"foo-9",
				"foo-10",
				"foo-11",
				"foo-12"
			),
			iteratesInAnyOrder(
				"foo-1",
				"foo-2",
				"foo-3",
				"foo-4",
				"foo-5",
				"foo-6",
				"foo-7",
				"foo-8",
				"foo-9",
				"foo-10",
				"foo-11",
				"foo-12",
				"foo-13"
			)
		);
	}
}