Make deprecated relations on App resource optional

[priitlatt]

Occasionally App Store Connect list apps and read app information endpoints respond with payloads where included application resources are lacking preOrder relationship, which is currently declared as mandatory.

That causes App object initialization to fail:

File "/usr/local/lib/python3.11/site-packages/codemagic/cli/action.py", line 83, in wrapper
    return func(self, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/codemagic/tools/app_store_connect/action_groups/beta_groups_action_group.py", line 33, in add_build_to_beta_groups
    matched_beta_groups, matched_beta_group_names = self._get_beta_groups(build_id, beta_group_names)
                                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/codemagic/tools/app_store_connect/action_groups/beta_groups_action_group.py", line 107, in _get_beta_groups
    app = self.api_client.builds.read_app(build_id)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/codemagic/apple/app_store_connect/builds/builds.py", line 96, in read_app
     return App(response["data"])
            ^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/codemagic/apple/resources/resource.py", line 253, in __init__
    self.relationships = self._create_relationships(api_response)
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/codemagic/apple/resources/resource.py", line 245, in _create_relationships
    return cls.Relationships(**defined_fields)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: App.Relationships.__init__() missing 1 required positional argument: 'preOrder'

Overcome this by making preOrder relationship optional.

It can also be seen that inAppPurchases relationship is marked as deprecated which means that it could be removed from response payloads in the future too. Mark that relationship as optional too for safety.