Move development tools out of runtime requirements

[Nameless-Monster-Nerd]

Summary

• move Ruff, pre-commit, and Dennis out of production requirements
• add a development requirements file that includes runtime dependencies
• keep the translation lint workflow reading the shared Dennis constraint
• document the contributor install command

Testing

• generated package metadata with python setup.py egg_info
• confirmed production metadata excludes ruff, pre_commit, and dennis
• confirmed all three constraints are present in requirements-dev.txt
• git diff --check

Fixes #4109.