Fix indentation for composite steps in reusable CI workflow

[RAprogramm]

Summary

• fix the indentation of the composite cargo steps in the reusable CI workflow so the YAML parses correctly

Testing

• cargo +nightly fmt --
• cargo +1.90.0 clippy --workspace --all-targets -- -D warnings
• cargo +1.90.0 test --workspace --all-features
• cargo deny check
• cargo audit --deny warnings

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https://chatgpt.com/codex/tasks/task_e_68db2d2f77fc832b992feb00259507ac