test(openapi): fix factory test for phpunit 13

[soyuka]

PHPStan (PHP 8.5) is currently red on 5.0 itself. This fixes it. 11 errors, one file,
two independent causes, both from test code that only ever compiled on 4.4.

I introduced this. #8562 landed on 4.4 green, and my 4.4 → 5.0 merge-up (81f2cdfe9)
carried it across with no textual conflict.

InvocationStubber::with(), 10 errors

Call to an undefined method PHPUnit\Framework\MockObject\InvocationStubber::with()

5.0 runs PHPUnit 13 since #8537, which changed what method() returns on a stubbed
double, so with() is gone from it. The five filter-locator doubles move to createStub
plus willReturnMap, matching the pattern the phpunit 13 migration already used in
src/State/Tests/CallableProcessorTest.php.

Worth noting these doubles assert nothing about being called, so createStub was the
correct tool all along and createMock was the wrong one before PHPUnit 13 ever made it an
error.

DefinitionNameFactory, 1 error

Class ApiPlatform\JsonSchema\DefinitionNameFactory does not have a constructor
and must be instantiated without any parameters.

__construct(?array $distinctFormats = null) exists on 4.4 and was removed on 5.0. The
helper no longer passes an argument. No other call site under src/OpenApi/Tests/ passes
one.

Verification

PHPStan on the file: 11 errors before, [OK] No errors after. The before state was
confirmed by swapping in the upstream/5.0 copy of the file rather than inferred.

All six affected tests pass individually.

Not addressed

Three untouched createMock() calls in the same helper raise a PHPUnit 13 notice
recommending createStub. They are notices, not errors, and PHPStan does not flag them, so
they are left out to keep this fix minimal while 5.0 is red. Worth a follow-up cleanup.