Fix cycle in the autopilot-cluster blueprint

[wiktorn]

Without this change, terraform errors with:
│ Error: Cycle: module.project.google_storage_bucket_iam_member.gcs-sinks-binding, module.project.google_project_iam_member.project-sinks-binding, module.project.google_essential_contacts_contact.contact, module.project.google_bigquery_dataset_iam_member.bq-sinks-binding, module.project.google_project_iam_member.bucket-sinks-binding, module.project (close), module.project.output.sink_writer_identities (expand), local.cluster_sa (expand), module.project.var.iam_bindings_additive (expand), module.project.google_project_iam_member.bindings, module.project.google_logging_project_sink.sink, module.project.google_pubsub_topic_iam_member.pubsub-sinks-binding

The actual error is wrong variable reference. 🤷

Maybe we need add tests for those blueprints

Closes: #2789

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Checklist

I applicable, I acknowledge that I have:

• Read the contributing guide
• Ran terraform fmt on all modified files
• Regenerated the relevant README.md files using tools/tfdoc.py
• Made sure all relevant tests pass

Closes: #2789

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Checklist

I applicable, I acknowledge that I have:

• Read the contributing guide
• Ran terraform fmt on all modified files
• Regenerated the relevant README.md files using tools/tfdoc.py
• Made sure all relevant tests pass