This isn't spawning from any previous security issue. Just adding an extra check to help ensure we don't ever regress this in the future.
```
AssertionError [ERR_ASSERTION]: We should not be leaking the `config.matrixAccessToken` to the Hydrogen render function because this will reach the client!
at renderHydrogenToString (matrix-public-archive\server\hydrogen-render\render-hydrogen-to-string.js:24:3)
at renderHydrogenVmRenderScriptToPageHtml (matrix-public-archive\server\hydrogen-render\render-hydrogen-vm-render-script-to-page-html.js:22:36)
at matrix-public-archive\server\routes\room-directory-routes.js:53:28
at processTicksAndRejections (node:internal/process/task_queues:96:5)
```
Follow-up to https://github.com/matrix-org/matrix-public-archive/pull/36
Render pipeline separation of concerns:
1. Run in `child_process`
2. Hydrogen render
It's now just a generic `child_process` runner that runs the Hydrogen render in it. This eliminates the windy path of the 1-4 steps that was only held together by the file names themselves.