Fix montgomery-shenzhen-indian-tbx11k datamodule

Trying to use the montgomery-shenzhen-indian-tbx11k datamodule would raise an error during batching as the tbx11k dataloader contains a "bounding-boxes" key which does not exist in the other ones.

The proposed fix is to add an ignore_bboxes parameter to the dataloader's constructor, which does not add the bounding boxes to the samples when set to True.