Allow unset PathItem method

[soyuka]

After disabling itemOperation GET

    itemOperations: [
        'get' => [
            'controller' => ApiPlatform\Core\Action\NotFoundAction::class,
            'read' => false,
            'output' => false,
        ],
    ]

there is not nice way to remove that path from OpenApi docs. Now to do
that you have to write:

$pathItem = $openApi->getPaths()->getPath('/resource/{id}');
$openApi->getPaths()->addPath(
    '/resource/{id}',
    new Model\PathItem(
        $pathItem->getRef(),
        $pathItem->getSummary(),
        $pathItem->getDescription(),
        null,
        $pathItem->getPut(),
        $pathItem->getPost(),
        $pathItem->getDelete(),
        $pathItem->getOptions(),
        $pathItem->getHead(),
        $pathItem->getPatch(),
        $pathItem->getTrace(),
        $pathItem->getServers(),
        $pathItem->getParameters(),
    )
);

After change it will be:

$pathItem = $openApi->getPaths()->getPath('/resource/{id}');
$openApi->getPaths()->addPath(
    '/resource/{id}',
    $pathItem->withGet(null)
);

Q	A
Branch?	main for features / current stable version branch for bug fixes
Bug fix?	yes/no
New feature?	yes/no
Deprecations?	yes/no
Tickets	Fix #...
License	MIT
Doc PR	api-platform/docs#...