Fix docs

Author: NicolasHug

src/torchcodec/encoders/_multi_stream_encoder.py

@@ -116,8 +116,6 @@ def add_video(
             width (int): The width of the **input** video frames.
             frame_rate (float): The frame rate of the **input** video frames.
                 Also defines the encoded **output** frame rate.
-            device (str, optional):
-
             device (str or torch.device, optional): The device to use for
                 encoding, e.g.  ``"cpu"`` or ``"cuda"``. If ``None`` (default), uses
                 the current default device.