fix: fix rle decode bug for empty string

Author: JoarGruneau

next_cvat/types/mask.py

@@ -182,7 +182,7 @@ def rle_decode(self) -> np.ndarray:
         Returns:
             A numpy 2D array of booleans representing the decoded mask
         """
-        counts = np.array([int(x) for x in self.rle.split(",")])
+        counts = np.array([int(x) for x in self.rle.split(",")] if self.rle != "" else [])
         total_pixels = self.height * self.width
 
         # Calculate positions where values change