refactor(data): move VLM sequence batching to collate#4315

yaoyu-33 wants to merge 2 commits into

kant/pr4169-unified-hf-datasetNVIDIA-NeMo/Megatron-Bridge:kant/pr4169-unified-hf-datasetfrom

franklin/pr4307-padding-collateNVIDIA-NeMo/Megatron-Bridge:franklin/pr4307-padding-collateCopy head branch name to clipboard