Feature Request Checklist

• I have read and agree to Mocha's Code of Conduct and Contributing Guidelines
• I have searched for related issues and issues with the faq label, but none matched my issue.
• I want to provide a PR to resolve this

Overview

In monorepos and other projects that have node_modules and/or .git directories deeper than the root, mocha --watch watches the contents of these directories by default.

(You may say, but in a monorepo you're just running tests in the directory for each individual package, where its node_modules lives, right? But sometimes you want to run integration tests that combine multiple packages in the monorepo.)

This generally causes mocha --watch to take a long time to start up, with no clear indication why.

Suggested Solution

If we changed the default watch-ignore to ["**/node_modules", "**/.git"] it would automatically ignore all such directories

Alternatives

Of course we can override this in userland, but I think it would benefit everyone to just ignore all node_modules and .git directories by default.

Additional Info

No response