🚀 Feature: if loading a file as CJS and ESM both fail, display both errors instead of just ESM

Feature Request Checklist

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

Overview

Ever since chai v5 dropped support for CJS, we get errors like this when we accidentally install chai 5+:

$ mocha 

 Exception during run: TypeError: Unknown file extension ".ts" for /Users/user/src/battalion/storage-site-sim/src/__tests__/SeededRNG.test.ts
    at Object.getFileProtocolModuleFormat [as file:] (node:internal/modules/esm/get_format:160:9)
    at defaultGetFormat (node:internal/modules/esm/get_format:203:36)
    at defaultLoad (node:internal/modules/esm/load:141:22)
    at ModuleLoader.load (node:internal/modules/esm/loader:409:7)
    at ModuleLoader.moduleProvider (node:internal/modules/esm/loader:291:45)
    at link (node:internal/modules/esm/module_job:76:21) {
  code: 'ERR_UNKNOWN_FILE_EXTENSION'
}

This threw us for a loop at first, because normally our tests work fine with @babel/register handling .ts files.

What's happening is first Mocha tries to load our file as CJS, which make it as far as require('chai') which fails with ERROR_REQUIRE_ESM. Then Mocha tries to load our file as ESM instead, which triggers the above error.

Alternatives

I've thought about adding code to our toolchain to check for chai v5+ and explicitly warn...but this same issue could occur with any package we're using in tests that drops CJS support

I guess another solution would be a mocharc option to force Mocha to only try one of CJS or ESM, not both.

I can't just put type: "commonjs" in my package.json because I made my toolchain run tests in CJS mode with @babel/register, and then in ESM mode with babel-register-esm, since I'm transpiling my TypeScript source to both CJS and ESM for publishing.

Additional Info

No response

mochajs / mocha