[APP-3269] Remove extra packages from new bare 3.12 python env

[kideh88]

This repository is public. Do not put here any private DataRobot or customer's data: code, datasets, model artifacts, .etc.

Summary

• Move to renamed dir
• Remove streamlit and other extra packages from the env
• Fix readme

Rationale

Users can define all requirements together with the Application source instead of us guessing which packages they might need.

[engprod-2[bot]]

The Needs Review labels were added based on the following file changes.

Team @datarobot/applications (#applications) was assigned because of changes in files:

public_dropin_environments/python312_streamlit/Dockerfile
public_dropin_environments/python312_streamlit/README.md
public_dropin_environments/python312_streamlit/env_info.json

Team @datarobot/custom-models (#custom-models) was assigned because of changes in files:

public_dropin_environments/python312/Dockerfile
public_dropin_environments/python312/README.md
public_dropin_environments/python312/__init__.py
public_dropin_environments/python312/env_info.json
public_dropin_environments/python312_streamlit/Dockerfile
public_dropin_environments/python312_streamlit/README.md
public_dropin_environments/python312_streamlit/env_info.json

If you think that there are some issues with ownership, please discuss with C&A domain at #core-backend-domain slack channel and create PR to update DRCODEOWNERS\CODEOWNERS file.

[engprod-2[bot]]

Label Needs Review: Custom Models was removed because @yakov-g is part of Custom Models domain.