Fix:
```sh
$ yarn run vite build -c vite.sdk-assets-config.js
yarn run v1.22.18
$ C:\Users\MLM\Documents\GitHub\element\hydrogen-web\node_modules\.bin\vite build -c vite.sdk-assets-config.js
locally linked postcss
cleanUrl(id) C:/Users/MLM/Documents/GitHub/element/hydrogen-web/src/platform/web/ui/css/themes/element/theme.css C:/Users/MLM/Documents/GitHub/element/hydrogen-web/src/platform/web/ui/css/themes/element/theme.css?type=runtime
[build-themes] Could not load C:/Users/MLM/Documents/GitHub/element/hydrogen-web/src/platform/web/ui/css/themes/element/theme.css?variant=light: ENOENT: no such file or directory, open 'C:\Users\MLM\Documents\GitHub\element\C:\Users\MLM\Documents\GitHub\element\hydrogen-web\src\platform\web\ui\css\themes\element\theme.css'
error during build:
Error: Could not load C:/Users/MLM/Documents/GitHub/element/hydrogen-web/src/platform/web/ui/css/themes/element/theme.css?variant=light: ENOENT: no such file or directory, open 'C:\Users\MLM\Documents\GitHub\element\C:\Users\MLM\Documents\GitHub\element\hydrogen-web\src\platform\web\ui\css\themes\element\theme.css'
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
```
Regressed in:
https://github.com/vector-im/hydrogen-web/pull/769/files#diff-5432b565e86d2514c825ed9972c37ea19820bf12b5d8d3203fc9d4ea4654bd34L20 where the `const path = require('path');` was removed but we also started using `path` in more places which needed the same treatment.
When making the fix, we also have to make sure we don't also regress:
https://github.com/vector-im/hydrogen-web/pull/750
From the console, I can click the source references in the stack trace
to jump to the spot in the code where things are going wrong.
It also helps with the problem of the error not having enough
space to be read in some components.
Split off from https://github.com/vector-im/hydrogen-web/pull/653
