fix: tests not matching any objects are not considered risky

[gehrisandro]

Starting from v2.2.3 Arch tests not matching any object are considered as successful instead of risky.

Given the following test:

test('global')
    ->expect('Invalid\Namespace')
    ->toUseStrictTypes();

v2.2.3 returns the following output:

v2.2.2 and before the test has been considered as risky:

This behaviour has changed here: https://github.com/pestphp/pest-plugin-arch/commit/f44834b728b44028fb7d99c4e3efc88b699728a8

From the commit message I can't figure out what the reason behind this change was. But I hope my PR does not mess up with it.

@nunomaduro Maybe you help me out here?