ci: add Autobahn RPC .io/.iox spec fixtures to integration tests (CON-256)

[wen-coding]

Summary

• Adds a new matrix entry "Autobahn RPC .io/.iox (spec fixtures)" to .github/workflows/integration-test.yml, sibling to the existing EVM RPC .io/.iox entry.
• Reuses the same evm_rpc_tests.sh driver against an Autobahn-enabled cluster (env: AUTOBAHN=true GIGA_EXECUTOR=true GIGA_STORAGE=true).
• This exercises the EVM RPC spec surface on the Autobahn consensus path, complementing the EVM-mode coverage we already run.

Test plan

Local verification on this branch:

• Brought up cluster with the exact matrix env (AUTOBAHN=true GIGA_EXECUTOR=true GIGA_STORAGE=true); all 4 nodes report GigaRouter initialized in their seid log and the chain advances.
• Ran GOWORK=off ./integration_test/evm_module/scripts/evm_rpc_tests.sh against the Autobahn cluster: 160/160 spec fixtures pass (100%).
• CI: confirm the new matrix entry comes up green in the Docker Integration Test workflow.

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Note

Low Risk
Low risk CI-only change that adds an extra matrix job; main impact is increased CI time or potential flakiness from running the same RPC fixtures under a different env configuration.

Overview
Adds a new integration-test matrix entry, "Autobahn RPC .io/.iox (spec fixtures)", which runs the existing evm_rpc_tests.sh suite with AUTOBAHN=true GIGA_EXECUTOR=true GIGA_STORAGE=true to exercise the same RPC spec fixtures on the Autobahn-enabled cluster path.

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[github-actions]

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Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	May 13, 2026, 4:38 PM