[LLM-SPOT INTEGRATION, WIP, DO NOT REVIEW] Use habitat-llm to call spot-sim2real lls

[jimmytyyang]

To achieve the design of using habitat-llm to call spot-sim2real, we made several design decisions

• Remove all the dependency of habitat-baselines in spot-sim2real. We are glad that we use torchscript to load skills in spot-sim2real, allowing us to have only one version of habitat-lab and habitat-baselines for habitat-llm.
• Update the environment yml for habitat-llm. Current spot-sim2real uses python3.8 to run the experiments. However, habitat-sim required by habitat-llm needs python3.9. We bump up the version of python to 3.9 in spot-sim2real. We will test this on hardware on Monday (Feb 5)
• We are able to run habitat-llm demo code in this new conda env that is compatible with spot-sim2real packages. We will release an installation readme.
• We will test this pipeline on hardware on Monday (Feb 5)