Suppress empty 3x3 warning.

5-metrics.py

@@ -101,6 +101,7 @@ def _read_center_pixel(path: Path, lat: float, lon: float) -> float | None:
         if nodata is not None:
             data = np.where(data == nodata, np.nan, data)
         data[data == 0] = np.nan
+        with np.errstate(all="ignore"):
             val = np.nanmean(data)
         return None if np.isnan(val) else float(val)
     except Exception:
@@ -310,6 +311,7 @@ def _read_multiband_center(
                 if nodata is not None:
                     data = np.where(data == nodata, np.nan, data)
                 data[data == 0] = np.nan
+                with np.errstate(all="ignore"):
                     val = np.nanmean(data)
                 result[name] = None if np.isnan(val) else round(float(val), 6)
         return result