Fix Mocha watch task by delegating to Node

[fatso83]

Since Node 18 there is a built-in watch mode. Mocha's watch mode is really buggy and this fix is much snappier and bug-free AFAIK.

Purpose (TL;DR) - mandatory

How to verify - mandatory

1. Check out this branch
2. npm install

Checklist for author

• [ ] npm run lint passes
• [ ] References to standard library functions are cached.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (45c4d6b) 96.02% compared to head (80b9289) 96.02%. Report is 1 commits behind head on main.

:exclamation: Current head 80b9289 differs from pull request most recent head a9ce9eb. Consider uploading reports for the commit a9ce9eb to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2573 +/- ## ======================================= Coverage 96.02% 96.02% ======================================= Files 40 40 Lines 1912 1912 ======================================= Hits 1836 1836 Misses 76 76 ``` | [Flag](https://app.codecov.io/gh/sinonjs/sinon/pull/2573/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=sinonjs) | Coverage Δ | | |---|---|---| | [unit](https://app.codecov.io/gh/sinonjs/sinon/pull/2573/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=sinonjs) | `96.02% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=sinonjs#carryforward-flags-in-the-pull-request-comment) to find out more.

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