REMOVE DEAD CODE

[Mohiiit]

Summary

This PR removes dead code paths and stale dead-code suppressions from the current main code path.

What Changed

• Removed the unused block metadata field that had no read path.
• Dropped stale dead_code suppressions where code is actively used.
• Removed the unused helper write_serializable_to_file from generate-pie.
• Kept behavior unchanged while tightening compile-time hygiene.

Validation

• cargo fmt --all --check
• cargo clippy -p generate-pie --all-targets -- -D warnings

Outcome

Cleaner codebase with stricter lint hygiene and no behavioral change.