build: onboard npm installs to CFS

[hallvictoria]

Description

Disable the Cosmos DB emulator’s bundled Data Explorer during emulator tests.

The Data Explorer entrypoint runs npm start inside the container, causing CFSClean violations from registry.npmjs.org. The tests do not use Data Explorer, so this change sets ENABLE_EXPLORER=false and removes the unused port 1234 mapping.

Example run from the emulator tests shows CFS compliancy: https://azfunc.visualstudio.com/public/_build/results?buildId=295892&view=logs&j=7aa5b4c0-a883-5879-6f42-8b22e5f7c769&t=286d7a0d-3562-5b60-b497-88ed2b1d4742

Fixes #

---

Pull Request Checklist

Host-Worker Contract

• Does this PR impact the host-worker contract (e.g., gRPC messages, shared interfaces)?
  • If yes, have the changes been applied to:
    • azure_functions_worker (Python <= 3.12)
    • proxy_worker (Python >= 3.13)
  • If no, please explain why:

Worker Execution Logic

• Does this PR affect worker execution logic (e.g., function invocation, bindings, lifecycle)?
  If yes, please answer the following:

Python Version Coverage

• Does this change apply to both Python <=3.12 and 3.13+?
• If yes, have the changes been made to:
  • azure_functions_worker (Python <= 3.12)
  • runtimes/v1 / runtimes/v2 (Python >= 3.13)
• If no, please explain why:

Programming Model Compatibility (for Python 3.13+)

• Does this change apply to both:
  • V1 programming model (runtimes/v1)?
  • V2 programming model (runtimes/v2)?
• Explanation (if limited to one model):