Test-only packages are in production dependencies

A few test libraries are listed under runtime dependencies instead of devDependencies, so they get installed in production builds unnecessarily.

Packages currently in runtime deps:

• sinon
• sinon-mongoose
• jest-express
• mongodb-memory-server

mongodb-memory-server is especially heavy and unnecessary for production installs.

Actual behavior:
Test tooling is shipped in runtime dependencies.

Expected behavior:
Test tooling should be in devDependencies only.

Steps to reproduce:

1. Open package.json.
2. Check the dependencies section.
3. Confirm the above test packages are listed there.

Why this matters:
Larger production install/build footprint.
Slower CI/build pipelines.
Unnecessary runtime dependency surface.

Environment:
Repo: processing/p5.js-web-editor
Date observed: 2026-02-21
Local dev setup on Windows