[Core] Disable conda activate for custom docker image as runtime environment

[cblmemo]

Blocked by #3867 and fixes #3741.

Tested (run the relevant ones):

• Code formatting: bash format.sh
• Any manual or new tests for this PR (please specify below)
  • vLLM docker image works:

resources:
  cloud: aws
  image_id: docker:vllm/vllm-openai:latest
  accelerators: T4
run: |
  # conda deactivate # <- dont need to deavtivate
  python3 -c "import huggingface_hub; huggingface_hub.login('hf_xxx')"
  python3 -m vllm.entrypoints.openai.api_server --model meta-llama/Llama-2-7b-chat-hf --tokenizer hf-internal-testing/llama-tokenizer --max-model-len 64

• All smoke tests: pytest tests/test_smoke.py
• Relevant individual smoke tests:
  • pytest tests/test_smoke.py::test_docker_storage_mounts
  • pytest tests/test_smoke.py::test_job_queue_with_docker
  • pytest tests/test_smoke.py::test_docker_preinstalled_package
• Backward compatibility tests: conda deactivate; bash -i tests/backward_compatibility_tests.sh

[Michaelvll]

nit: Can we just use .format for this purpose? Having a lambda function in the constants.py is a bit weird.

[cblmemo]

I actually tried, but .format does not work for those {} in the installation commands..

[Michaelvll]

I see, in that case, let's have a comment here for why we use lambda function here. : )

[cblmemo]

Smoke test for this also passed!