gguf Composer MosaicML llm-foundry StreamingDatasets dataset:allenai/c4 dataset:mc4 dataset:togethercomputer/RedPajama-Data-1T dataset:bigcode/the-stack-dedup dataset:allenai/s2orc arxiv:2108.12409 arxiv:2302.13971 arxiv:2205.14135 arxiv:2010.04245 arxiv:1909.08053 arxiv:2302.06675 license:apache-2.0 region:us