Use pathlib in DOTA ops (#7552)

Signed-off-by: Glenn Jocher <glenn.jocher@ultralytics.com>

ultralytics/utils/loss.py

@@ -38,9 +38,7 @@ class VarifocalLoss(nn.Module):
 class FocalLoss(nn.Module):
     """Wraps focal loss around existing loss_fcn(), i.e. criteria = FocalLoss(nn.BCEWithLogitsLoss(), gamma=1.5)."""
 
-    def __init__(
-        self,
-    ):
+    def __init__(self):
         """Initializer for FocalLoss class with no parameters."""
         super().__init__()