Linter reports unused variables in `IQB_Map.py`

[arvinder004]

When running uv run ruff check . I got two F841 warnings in the prototype page:

• suffix is assigned but never used in _build_metrics_from_row
• found is set inside a loop but never read (the break already stops it)

These are harmless but clutter the linter output. The fix is simply to remove the two assignments.

This is a tiny clean‑up, no behaviour change.