Return grid square dm even if not present

Author: stephen-riggs

src/murfey/workflows/spa/flush_spa_preprocess.py

@@ -212,12 +212,13 @@ def _grid_square_metadata_file(f: Path, grid_square: int) -> Optional[Path]:
     """Search through metadata directories to find the required grid square dm"""
     raw_dir = f.parent.parent.parent
     metadata_dirs = raw_dir.glob("metadata*")
+    gs_path = None
     for md_dir in metadata_dirs:
         gs_path = md_dir / f"Metadata/GridSquare_{grid_square}.dm"
         if gs_path.is_file():
             return gs_path
-    logger.error(f"Could not determine grid square metadata path for {f}")
-    return None
+    logger.error(f"Grid square metadata path {gs_path} does not exist for {f}")
+    return gs_path
 
 
 def _flush_position_analysis(