Proactively ignore `venv/`, `__pycache__/`, `node_modules/`, etc. during submission?

Some students inadvertently include directories like `venv/`, `__pycache__/`, and `node_modules/` in their submissions. Some of these folders often contain tens of thousands of files, which can cause submit50 to break (lib50 to be precise) or significantly slow down. In some cases, these submissions even crash the autograder.