Adobe commerce remove broker id from subscription response

Remove broker id from api response. Broker id will be set with async webhook -> controller update Linear task

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[ ] The title of the PR uses business wording, not technical jargon, for the changelog readers to understand it
[ ] The PR implements the changes asked in the referenced task / issue
[ ] The automated tests are compliant with the testing strategy
[ ] The tests are relevant, and cover the corner/error cases, not only the happy path
[ ] You understand the impact of this PR on existing code/features
[ ] The changes include adequate logging and Datadog traces
[ ] Documentation is updated (API, developer documentation, ADR, Notion...)

alma / alma-monthlypayments-magento2