Drop pypi/npm release workflows | update the docs

[farhan]

Summary

Drop the automated release workflows (PyPI and npm) from mockprock, and update the docs both on mockprock and edx-proctoring.

mockprock is a mock proctoring backend used only for local development and testing of edx-proctoring. It has no consumers that install it from PyPI or npm, so release automation adds maintenance overhead and secrets exposure for no benefit.

Decision was done in aximprovements team weekly meeting, here are the notes

Background

• The npm semantic-release pipeline (.github/workflows/release.yml) runs on every push to master.
• During the uv + pyproject.toml modernization (feat: modernize mockprock to uv + pyproject.toml (pylint retained, no ruff) #66) it was retained and only updated to gate on CI; the decision to publish releases was never revisited.

Here is the followup deep down story on the publishing: #69

Tasks

mockprock (PR #71)

• Remove .github/workflows/release.yml and any semantic-release config it depends on.
• Do not add a PyPI publish workflow / python-semantic-release.
• Drop npm publish-only metadata that no longer applies (e.g. publishConfig in package.json).
• Update README.rst: state the no-release policy (as a note) and point to the edx-proctoring developing guide for local setup, rather than duplicating the steps.

References

• Modernization PR: feat: modernize mockprock to uv + pyproject.toml (pylint retained, no ruff) #66

[farhan]

Implemented. PR:

• mockprock (drop release workflows + README docs): build!: drop automated PyPI/npm release workflows; document release policy #71