chore: Fix mocha in Node v22+

[rschristian]

Alternative to #4629, should be much safer.

Basic gist is that require(esm) seemingly begins to parse modules to determine whether it's CJS or ESM, and in the case of the latter, require hooks are not yet supported against ESM modules so Babel doesn't transform the JSX within.

---

From Joyee's blog:

So that led to this PR. The major difference between this and the PR in 2019 was that this tried to keep the scope of require(esm) small and only supported loading synchronous ESM. As it turned out, this is not a controversial idea among collaborators/TSC at all and landed without much pushbacks (it derailed a tiny bit due to the discussions about loader hooks, but at least we agreed that hooks support could be left for follow-ups and require(esm) itself should be back on track).

https://joyeecheung.github.io/blog/2024/03/18/require-esm-in-node-js/

[coveralls]

coverage: 99.609%. remained the same
when pulling 61d15bb on chore/node-22
into a54a914 on main.

[marvinhagemeister]

LGTM, would do a quick format because newlines are missing at the end.

[rschristian]

Do we want newlines? Our editor config disables those for .json files:

preact/.editorconfig

Lines 10 to 13 in 2a788d6

	[{*.json,.*rc,*.yml}]
	indent_style = space
	indent_size = 2
	insert_final_newline = false

Will check with biome shortly, not sure what it enforces by default

Edit: Our editorconfig & biome settings were indeed conflicting, I edited the editor config as most of our other files were missing line endings so it makes sense to match biome.